Methods and systems for improving airway patency

ABSTRACT

An oral device for improving airway patency comprises a tongue constraint and a negative pressure source. The tongue constraint engages the patient&#39;s tongue to maintain a clear region below the palate in an oral cavity. By applying a negative pressure in the clear region, an airway behind the soft palate or tongue of the patient can be maintained. The tongue constraint is usually connected to an anchor. The anchor may be held between the patient&#39;s teeth or may engage the inferior surface of the palate. Another oral device for improving airway patency comprises a lateral tongue structure and a negative pressure source.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of provisional U.S.Application No. 60/987,707 (Attorney Docket No. 027094-000100US), filedNov. 13, 2007, the full disclosure of which is incorporated herein byreference. This application is related to commonly-assigned U.S.application Ser. No. ______ (Attorney Docket No. 027094-000120US) andU.S. application Ser. No. ______ (Attorney Docket No. 027094-000130US),both filed on the same day as the present application and both of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to medical devices and methods.In particular, the present invention relates to an oral device that maybe held in the mouth of a patient to reduce the incidence of obstructivesleep apnea or snoring.

Obstructive sleep apnea (OSA) is a serious medical condition resultingfrom a temporary airway blockage which occurs as a patient sleeps. Theairway blockage usually occurs between the soft palate and/or the backof the tongue and the pharynx. As the patient breathes, the reduced areain the upper airway can cause snoring, and more seriously, OSA.

Sleep disruption caused by OSA can result in severe daytime sleepiness,chronic fatigue, headaches, depression, accidents, injuries, and ofparticular concern, OSA can reduce the amount of oxygen entering thelungs causing hypoxia. Hypoxia, in turn, can lead to pulmonaryhypertension, heart disease, and stroke.

Numerous invasive and less invasive treatments have been proposed forOSA. Of particular interest to the present invention, “continuouspositive airway pressure” (CPAP) delivers a continuous stream ofpressurized air directly to the person's upper airway. The positivepressure maintains patency of the airway and inhibits the collapseassociated with OSA. Although generally effective, CPAP suffers from anumber of drawbacks that have led to a high level of non-compliance. Thepatient must wear a bulky facial mask which can be uncomfortable, andthe system generates noise that can make falling asleep difficult. CPAPis also difficult to use because the mask requires careful fitting toavoid air leaks and facial discomfort and because the mask can easily bedislodged during sleep. Moreover, a number of unpleasant side effects,such as sore throats, dry throat and eyes, headaches, and skin rashesfrom the mask frequently occur. These problems have resulted in a highlevel of non-compliance with CPAP therapy.

As an improvement over CPAP, it has been proposed to apply a negativepressure to the forward end of the patient's mouth, typically at or justbehind the lips, to pull the tongue forward in order to lift the rearportion of the tongue away from the back of the airway. See, forexample, U.S. Patent Publication Nos. 2007/0277818, 2005/0166928 and2005/0166929. While promising in theory, in practice it is verydifficult to apply a vacuum in the region of the tip of the tongue toraise the base of the tongue and clear the patient's airway,particularly when the patient is lying on his or her back and gravity ispulling the tongue posteriorly. The tongue is a relatively large andcompliant organ with significant mass, and applying a vacuum over arelatively small surface area at the tip will often not be effective inraising the back of the tongue against gravity. The moist and complianttissues in the mouth are somewhat self-sealing, and this effect tends toinhibit the propagation of negative pressure, thereby confining thenegative pressures to a relatively small area near the point ofapplication. Thus, simply applying a vacuum at a location near theanterior tip of the tongue tends to draw the tongue up against the hardpalate posterior to this location, creating a seal that restricts thepropagation of vacuum through this region of contact toward the back ofthe oral cavity, where direct vacuum is usually required for maximumeffectiveness.

As another improvement over CPAP, it has been proposed to place variousdevices in direct contact with the posterior tissues of the mouth suchas the soft palate and posterior portions of the tongue. A majordisadvantage of these approaches is that contact with certain tissuesnear the posterior area of the tongue may elicit the gag reflex and inany case the presence of such devices so far back in the mouth can beuncomfortable.

For these reasons, it would be desirable to provide alternative andimproved methods and apparatus for treating obstructive sleep apnea andsnoring. The methods and devices should be non-invasive and require nosurgery or permanently implanted components. In addition, the methodsand devices should be minimally intrusive with components that arecomfortable and quiet so that disruption of the patient's sleep isminimized. Moreover, the methods and devices should avoid contacting theportions of the oral cavity that trigger the gag reflex. The methods andsystems should also be simple to implement and be effective tosignificantly improve patency of a patient's airway during sleep. Atleast some of these objectives will be met by the inventions describedhereinafter.

2. Description of the Background Art

Oral and external devices for treating sleep apnea and snoring aredescribed in U.S. Patent Publication Nos. US2005/166929; US2005/166928;US2008/0188947; US2007/0277818; US2008/0216843; and US2008/0210244; andin U.S. Pat. Nos. 7,182,082; 7,073,506; 7,073,505; 6,955,172; 6,877,513;6,494,209; 5,957,133; 5,465,734; 4,676,240; 4,304,227; 4,169,473; and3,132,647; and in Cartwright and Samelson “The effects of a non-surgicaltreatment for obstructive sleep apnea: the tongue retaining device;”Journal of the American Medical Association 248 (1982).

BRIEF SUMMARY OF THE INVENTION

The present invention provides methods and systems for improving airwaypatency in patients by creating a clear region or space above the tongueand applying a negative pressure within the clear region. The clearregion creates an opening facing toward the soft palate upon which thenegative pressure may act. The negative pressure acts to draw the softpalate away from the pharynx and usually to draw the rear portion of thetongue away from the pharynx as well. The clear region may also serve tocreate a space into which the soft palate may move while negativepressure continues to act on its free surface. In this way, the softpalate and posterior tongue are urged anteriorly without contactingtissues in a way that might elicit the gag reflex. By moving the softpalate and optionally the tongue in a forward or anterior direction, thepatency of the airway behind the palate and tongue is enhanced toimprove breathing. Usually, while the negative pressure is beingapplied, the patient's lips will be closed or sealed to inhibit theentry of air into the clear region. Additionally, application of thenegative pressure will usually draw the soft palate into partial orcomplete contact with a surface of the rear tongue or with the deviceitself so as to create a seal which substantially fluidly isolates theairway from the clear region. In that way, the desired negative pressuremay be maintained within the clear region with minimum air or fluid flowneeded to maintain the negative pressure within the region. Becausefluid flow is minimized this therapy can be very quiet andenergy-efficient.

As used herein, “superior” refers to the direction toward the top of theoral cavity (or top of the head), “inferior” refers to the directionopposite the superior direction, “anterior” refers to the directiontoward the front of the oral cavity or lips, and “posterior” refers tothe direction toward the back of the oral cavity and airway, oppositethe anterior direction. The terms “patency” and “airway” refer to theopening or clearing of the airway leading from the nasal cavity into thetrachea located generally behind the soft palate and the rear of thetongue. To improve airway patency, the airway may be wholly or partiallyobstructed intermittently or temporarily for some time period over anormal sleep cycle, however, the airway will be open or partially openmore than it would in the patient's untreated condition. The “upperportion of the soft palate” refers to the superior portion of the softpalate extending inferiorly from the end which connects to the hardpalate to a point about ⅓-½ way toward the free inferior tip of the softpalate. The phrase “medial region” or “medial surface” of the tonguerefers to a superior surface of the tongue which is spaced substantiallyposteriorly from the anterior tip of the patient's tongue andimmediately anterior or forward of the region which initiates the gagreflex. While it may vary from patient to patient, the medial regionwill generally be the middle one third of the upper surface of thetongue which extends between the anterior tip of the tongue and theposterior end of the tongue (the posterior end being the location on thetongue that is furthest posterior in the oral cavity); i.e., the medialsurface will usually include an area of the tongue that is at leastabout ⅓ of the way, more preferably at least about ½ of the way, fromthe anterior tip of the tongue to the posterior end of the tongue.Preferably, the medial region will include an area on the tongueposterior to the midpoint between the anterior and posterior ends of thehard palate. The phrase “clear region” refers to the space or volumeabove the tongue which will be cleared by the methods and devices of thepresent invention. The clearing will usually be achieved by engaging asurface against the superior surface of the tongue, typically using amember or element which engages the tongue and which is anchored withinthe oral cavity so as to constrain the tongue from raising into theclear region to interrupt the negative pressure which is beingmaintained. The term “vacuum” and the phrase “negative pressure” eachrefers to a total or partial vacuum which is maintained in the clearregion, typically by controlled aspiration, where the pressure ismaintained primarily in the range from 5 cm H₂O to 150 cm H₂O below thelocal atmospheric pressure. The “occlusal plane” is the plane in whichthe upper and lower teeth meet when the patient bites the upper andlower teeth together.

In a first specific aspect of the present invention, methods forimproving airway patency in a patient comprise constraining a medialsurface of the patient's tongue to maintain a clear region below thepalate in an oral cavity. Negative pressure is applied within the clearregion to open an airway behind the soft palate. Typically, the appliednegative pressure closes a posterior portion of the soft palate againstthe tongue to draw the soft palate forward which in turn opens theairway behind the soft palate. By closing the soft palate against thetongue, the rear of the oral cavity is at least partially sealed so thatthe negative pressure applied within the clear region can be more easilymaintained and can more readily draw both the soft palate tissue and therear tongue tissue in a forward direction to help open the airway in thepharynx. The front of the oral cavity may also be at least partiallysealed in order to inhibit air from entering the mouth. This may befacilitated by providing a sealing structure between the upper and lowerlips and/or by providing a sealing structure between the lips and theteeth.

Constraining the medial surface of the patient's tongue may beaccomplished in a variety of ways. Typically, a tongue constraint willbe engaged against the medial surface to either depress the tongue ormaintain the tongue in a lowered or depressed configuration (relative tothe roof of the oral cavity) to provide the desired clear region belowthe palate and above the tongue. Typically, the constraint has a flat oran arch-like structure and may have a generally concave surface whichengages the tongue. The tongue will typically be engaged at a pointforward of a gag reflex response region, and the negative pressure isapplied using a vacuum source positioned proximate the clear region,either within the clear region or adjacent to it. Typically, the vacuumsource will have a plurality of ports or openings which permit adistributed aspiration of air and fluids from the clear region withinthe oral cavity. Often, multiple vacuum sources such as probes, portionsof the tongue constraint, or portions of other structures describedhereinafter, may be employed to again improve the distribution of theaspiration within the clear region. Usually, the distributed negativepressure or aspiration ports will be positioned within the clear regionor adjacent rear portions of the oral cavity in order to assure that thedesired negative pressure within the clear region is achieved. This isin contrast to prior art where the vacuum source may be positioned in aforward region of the oral cavity, typically behind the lips, generallyin the region of the front teeth. Negative pressure or aspiration portsmay also be positioned to apply negative pressure to other posteriorportions of the mouth such as the sides of the tongue. Such ports mayaid in urging portions of the tongue and soft palate forward by applyingnegative pressure into posterior oral spaces that can be at leastpartially sealed off by the compliant tissues of the mouth. It may beadvantageous to apply different levels of negative pressure at variouslocations.

In preferred aspects of these methods for improving airway patency,remaining portions of the tongue will typically not be constrained, andthe level of negative pressure applied within the clear region may beadjusted for comfort, to improve efficacy, or for other purposes. Inaddition, it may be desirable to deliver a fluid, such as water,humidified air, or the like, in order to moisten the oral cavity whichmight become dry after a prolonged exposure to aspiration. The fluidwill typically be delivered during the application of negative pressure,but could also be delivered before, after, and at other times. In otherinstances, the mouth may be too moist, and fluid such as saliva or mucuswill accumulate, in which cases it will be desirable to aspirate fluidwhich accumulates in the oral cavity, possibly through a separatenegative pressure line. Aspiration of accumulated fluid will reduce theneed for the patient to swallow during sleep and may be aided bydelivery of additional fluid to the oral cavity such as air as describedabove.

In a second specific aspect of the present invention, methods forimproving airway patency comprise positioning an anchor structure in apatient's oral cavity. The anchor structure typically carries or isotherwise coupled to a tongue constraint which engages a medial surfaceof the patient's tongue to maintain a clear region below the palate. Anegative pressure is applied by a vacuum source which is positionedproximate the clear region of the oral cavity, where the negativepressure closes a posterior portion of the soft palate against thetongue to draw the soft palate forward. Often, the at least one vacuumsource is coupled to or integral with the anchor structure so that thevacuum source is positioned proximate the clear region when the anchorstructure is properly in place. Alternatively, the at least one vacuumsource could be positioned separately from the anchor structure, inwhich case it will typically be formed as a separate probe or otherassembly.

The anchor structure may comprise a bite structure which is held by thepatient between the patient's teeth. Typically the bite structure willcomprise at least one bite surface which is held between the teeth and alip seal which helps seal the oral cavity when the bite structure is inthe mouth. Alternatively, the bite structure may comprise upper andlower tooth-receiving channels which both receive the teeth and helpseal the oral cavity when the bite structure is in the mouth. As analternative to such bite structures, the anchor may comprise a hardpalate engagement surface which is held in engagement against the hardpalate (the roof of mouth) to hold the anchor in position to maintainthe clear region.

The negative pressure may be applied in a variety of ways, usually beingapplied through a plenum network in the anchor or through a separatevacuum source or probe. Usually, the plenum will be present in theanchor structure, for example extending at least through the tongueconstraint. Alternatively or additionally, the plenum could extendthrough the bite structure, or in other embodiments could be formedseparately from the anchor. In still further embodiments, the plenumnetwork will be configured to extend laterally in the oral cavity downat least one side of the tongue, preferably down both sides of thetongue and in a generally posterior direction so that the plenum networkcan distribute negative pressure to posterior areas of the oral cavitythat may otherwise be sealed off by the compliant tissues of the mouth.

In a third specific aspect of the present invention, an oral devicecomprises an anchor structure having a lip seal. A tongue constraint iscoupled to the anchor structure so that the constraint engages a medialsurface of the tongue when the lip seal is positioned against thepatient's lips. A plenum or other network or means for applying anegative pressure in a region above the medial surface of the tongue isalso provided in order to draw the soft palate inferiorly and anteriorlyon the posterior region of the tongue when the anchor structure andtongue constraint are in place.

In preferred aspects of the oral device, the lip seal is configured tobe positioned between the teeth and the lips, optionally comprising abite structure, such as a U-shaped frame having a closed forward end andan open rearward end, more typically comprising a pair of bite surfaceswhich define the U-shaped frame wherein the lip seal is disposed at theclosed forward end of the frame. Alternatively, the bite structure maycomprise upper and lower tooth-receiving channels, which define theU-shaped frame. The lip seal additionally or alternatively may beconfigured to be positioned between the upper lip and the lower lip. Asan alternative or an addition to the bite structure, the oral device maycomprise a hard palate engagement surface. The hard palate engagementsurface will be configured to engage the hard palate in order to holdthe tongue constraint against the tongue to form the clear regionwherein the negative pressure will be applied.

The tongue constraint may also comprise a variety of configurations.Typically, the tongue constraint may be a plate disposed laterallyacross a rearward portion of the anchor structure. The plate maycomprise an arch configured to extend over the tongue and apply a forcein the inferior direction.

The negative pressure applying means may also have a wide variety ofconfigurations, but will typically include at least one vacuum port, andusually include a plenum network in any one or more of the anchorstructure, tongue constraint, or other portions of the device. Inparticular, the negative pressure plenum may be present in the tongueconstraint, in the bite structure, in the anchor structure, and mostoften in the tongue constraint which is positioned at the bottom of theclear region where it is desired to draw the negative pressure. Thenegative pressure plenum could also be formed in a separate structureattached or otherwise coupled to the anchor, and such separatestructures will typically extend inferiorly into the oral cavity, moretypically on either or both sides of the tongue. Of course, in manycases, it will be desirable to have the plenum formed in the anchorstructure, bite structures, tongue constraints, as well as in separatecomponents in order to maximize exposure of the clear region to thenegative pressure source. A negative pressure port or plenum may alsoextend directly to the space lateral to the posterior portion of thetongue in order to further draw the oral tissues away from the airway.

In a fourth aspect of the present invention, systems are providedincluding an oral device as generally described above in combinationwith a vacuum source connectable to the negative pressure applyingmeans. The vacuum source will typically comprise a pump, where aflexible tube is provided between the pump and the negative pressureplenum or other means in the oral device. The system may furthercomprise a pressure sensor present on the oral device and a pressurecontroller within or connectable to the vacuum source, whereby a desiredvacuum level may be maintained within the clear region in the oralcavity. Other specific control and pumping features are described indetail below.

In a fifth aspect of the present invention a method and device areprovided which do not require that a clear region be created below thepalate in the oral cavity. The device comprises an anchor structure anda means for applying a negative pressure directly to at least one regionlateral to a posterior region of the tongue. Any of the various plenumstructures which align a vacuum source on either or both sides of thetongue, as described above, would be suitable. Methods comprise applyinga negative pressure to at least one region lateral to a posteriorportion of the tongue in the oral cavity to open the airway behind thesoft palate. Optionally, a clear region below the palate may be opened,and a negative pressure applied therein to enhance opening of theairway.

In a further aspect of the invention, a method for improving airwaypatency in a patient comprises the steps of placing an oral device inthe oral cavity, the oral device having a tongue constraint to engage amedial surface of the tongue, the tongue constraint constraining themedial surface in a position spaced-apart from the hard palate, wherebya continuous vacuum flow path extends from the lips to the soft palate;and applying a vacuum through the vacuum flow path directly to the softpalate such that the soft palate forms a seal against one or both of thetongue and the oral device such that the airway is substantially fluidlyisolated from the vacuum flow path.

The tongue constraint will engage and constrain the tongue over an areaselected so that the tongue cannot be drawn upward into contact with aposterior portion of the hard palate when the vacuum is applied suchthat the vacuum flow path becomes obstructed. Because the tongue is softand compliant, application of vacuum between the tongue and palate willdraw the tongue up against the hard palate unless it is physicallyconstrained at the location where a clear region is desired. If notconstrained in this manner, this contact between tongue and palate willcreate a seal that restricts the propagation of vacuum through thisregion of contact toward the soft palate. Therefore a clear region mustbe maintained particularly in the region of the soft palate in order toeffectively apply vacuum forces to the soft palate. This usuallyrequires that the tongue be engaged in an area substantially posteriorto its anterior tip. In most embodiments, the tongue constraint engagesthe medial surface at a point at least about ⅓ of the distance from ananterior tip of the tongue to a posterior end of the tongue. Preferably,the tongue constraint engages the medial surface at a point posterior tothe midpoint between the anterior and posterior ends of the hard palate.The tongue constraint may engage the tongue as far back as 20 mmposterior to the posterior end of the hard palate where it joins to thesoft palate. Optionally the tongue constraint may extend anteriorly toor near the front teeth so as to engage the anterior tip of the tongue,but alternatively the tongue constraint may be spaced posteriorly fromthe front teeth so as to engage only the medial surface of the tongue.Laterally, the tongue constraint will preferably have a shape and sizeadapted to engage and constrain at least a majority of the width of thetongue. In most embodiments the tongue constraint will spansubstantially the entire space between the patient's molars.Alternatively the tongue constraint may be configured to engage only amiddle portion of the tongue with lateral areas of the tongue remainingunconstrained, or to engage only lateral portions of the tongue with themiddle portion unconstrained.

The oral device will mechanically enforce the vacuum flow path to ensureit is continuous from the front of the oral cavity to the soft palate;in some embodiments, the device itself engages tissue alongsubstantially all or a majority of the vacuum flow path to keep it open;in other embodiments, the device engages tissue along a posteriorportion of the vacuum flow path, particularly in the medial region ofthe tongue and posterior thereof, in a manner which maintains thepatency of the entire vacuum flow path. Usually the vacuum flow pathwill comprise a clear region formed between the tongue and the hardpalate. Some portions of the tongue may engage the hard palate, howevera sufficient portion of the tongue will be spaced-apart from the hardpalate so as to create a continuous vacuum flow path from the front ofthe oral cavity to the soft palate. The clear region is in fluidcommunication with the soft palate through an opening facing away fromthe tongue and preferably in a posterior direction toward the softpalate. The vacuum flow path may also comprise a vacuum lumen integralwith or coupled to the oral device. Such a vacuum lumen may route thevacuum flow path in a manner that avoids the region between the anteriorportion of the tongue and hard palate by routing the vacuum lumen aroundthe outside of the teeth, through the bite line, around the lateraledges of the tongue, or below the tongue. With such configurations, theanterior portion of the tongue may contact the hard palate withoutaffecting vacuum delivery to the soft palate.

The method may further comprise the step of delivering positive pressureto the airway posterior to the seal. Preferably the positive pressure isdelivered through the oral cavity, but alternatively could be deliveredthrough the nasal airway.

Vacuum may be applied through a first port oriented away from the tonguesuch that the first port remains unblocked by the tongue. Preferably,the first port is disposed over or posterior to the medial region of thetongue, preferably being posterior to the midpoint between the anteriorand posterior ends of the hard palate. Further, the first port ispreferably oriented in a direction so as to apply vacuum directly to ananterior surface of the soft palate. Usually, the soft palate willengage a posterior portion of the oral device when vacuum is appliedthrough the first port. In addition the method may include applying avacuum to a superior surface of the tongue. The vacuum is usuallyapplied to the superior surface of the tongue through an inferior portin the oral device. Vacuum may also be applied to a lateral surface ofthe tongue or to other posterior oral tissues. Usually, the vacuum has anegative pressure in the range from −5 cm H₂O to −150 cm H₂O.

The method will usually include sealing the patient's lips to inhibitair entering the oral cavity while the vacuum is being applied. The lipsmay be sealed by placing a sealing structure between the lips and theteeth, between the lips, or on the outside of the lips. The method mayfurther include the step of positioning a pressure monitor in the oralcavity to monitor for leaks.

In addition, saliva may be aspirated from the oral cavity by the vacuum.Preferably the saliva is aspirated so as to minimize any variation inthe vacuum pressure applied within the oral cavity. This may beaccomplished by the use of a vent in communication with the vacuum flowpath. In some embodiments, the method includes maintaining asubstantially constant vacuum pressure while the saliva is beingaspirated.

The method may optionally include the step of repositioning thepatient's jaw into a first position, and maintaining the jaw in thefirst position while the vacuum is applied. The first position may be aslightly jaw-open position, in which the upper and lower teeth are heldslightly apart from each other, or an anterior position in which thelower jaw is held slightly anterior of its normal, relaxed position.

In still another aspect, the invention provides a method for improvingairway patency in a patient comprising the steps of constraining asuperior surface of the patient's tongue to maintain a clear regionbetween the superior surface and the hard palate, the clear region beingin fluid communication with the soft palate through a posterior openingfacing in a posterior direction toward the soft palate; and applying anegative pressure within the clear region to hold the soft palate in aposition in which airway is at least partially open, wherein theposterior opening remains unobstructed by the tongue when the negativepressure is applied. Using the methods of the invention, the airway maybe wholly or partially obstructed for short time periods over apatient's sleep cycle, however, these time periods will be less than inthe patient's untreated condition. In a preferred aspect the posterioropening lies in a first plane which is disposed at an angle of at leastabout 45 degrees, more preferably at least about 90 degrees, relative toan occlusal plane defined by a plane of contact between the patient'supper and lower teeth. In this way, the posterior opening is configuredto apply negative pressure directly to at least the upper portion of thesoft palate when the airway is unobstructed.

The medial surface of the tongue is usually constrained by a tongueconstraint positioned in the patient's oral cavity so as to create theclear region. Usually the tongue constraint engages the medial surfaceat a point at least about ⅓ of the distance from an anterior tip of thetongue to a posterior end of the tongue. Usually the tongue constraintalso engages the medial surface at a point at least ½ the distance fromthe anterior to the posterior ends of the hard palate. In addition, thetongue constraint will preferably have a shape and size adapted toengage and constrain at least a majority of the width of the tongue. Inthis way the clear region and the posterior opening are defined on aninferior side by the tongue constraint and on a superior side by thepatient's hard or soft palate. The clear region may be in communicationwith at least one inferior port in the tongue constraint facing towardthe tongue such that when negative pressure is applied at least oneinferior port is blocked by the tongue while the posterior openingremains unblocked by the tongue. In a preferred aspect of the method,the soft palate engages the tongue, the tongue constraint, and/oranother structure coupled to the tongue constraint to create a sealwhich substantially fluidly isolates the airway from the clear region.Usually the method also includes placing a lip seal along the patient'slips to help seal the oral cavity when the negative pressure is applied.

Negative pressure may be applied through at least one vacuum lumen orplenum network coupled to or integral with the tongue constraint. Thevacuum lumen or plenum network may alternatively be coupled to orintegral with a bite structure to which the tongue constraint isattached. The plenum network or vacuum lumen may also extend down atleast one lateral side of the tongue. Alternatively negative pressuremay be applied through at least one vacuum lumen positioned in the oralcavity separately from the tongue constraint.

Usually the method will include positioning an anchor structure in theoral cavity, the tongue constraint being coupled to or integral with theanchor structure. In some embodiments, positioning the anchor structurecomprises holding a bite structure between the teeth. Alternativelypositioning the anchor structure may comprise engaging a hard palateengagement surface against the hard palate to hold the anchor inposition. Preferably, the tongue constraint comprises a plate having awidth at least about ½ the width of the tongue. The plate may havelateral edges extending from an anterior to a posterior end thereof, thelateral edges being fixedly attached to the anchor structure.

The method may further include either or both the steps of detecting aleak in the sealed region of the oral cavity with a detector positionedin the oral cavity, or receiving an indication of airway patency from asensor positioned in the oral cavity. For this purpose, the oral devicemay include one or more sensors coupled thereto, such sensors comprisingpressure sensors, flow sensors, temperature sensors, oximetry sensors,piezoelectric sensors, accelerometers, moisture sensors, contactsensors, or other types of sensors.

In addition the method may include aspirating liquid which accumulatesin the oral cavity. Preferably, liquid is aspirated so as to minimizeany pressure variation within the oral cavity. In one embodiment, a ventin communication with the vacuum flow path may be used to accelerateclearing of liquid from the vacuum flow path. In such cases the methodusually comprises maintaining a substantially constant negative pressurewhile the liquid is aspirated. Typically the liquid is saliva.

The method may also include a step of delivering positive pressure tothe airway while the negative pressure is applied. The positive pressuremay be delivered via the oral cavity or via the nasal airway.

In other embodiments the method further comprises repositioning thepatient's jaw from an undeflected position to a deflected position, andmaintaining the jaw in the deflected position while the negativepressure is applied. The deflected position may be a position anteriorto the patient's natural lower jaw position, or a position in which theupper and lower jaws are slightly apart.

In a further aspect, the invention provides a method for improvingairway patency in a patient comprising applying a first pressure througha first port at a first location in the patient's oral cavity; andapplying a second pressure through a second port at a second location inthe patient's oral cavity, the second pressure being different than thefirst pressure; wherein the tongue and soft palate are held in aposition in which airway is at least partially open. Usually at leastone of the first and second pressures will be negative pressure.

Usually the first pressure is applied to the tongue through the firstport, and the second pressure is applied to the soft palate through thesecond port. Typically the first and second ports are each coupled to anoral device positionable in the oral cavity. The first and second portsmay be movable relative to each other within the oral cavity.

The method may also include constraining the tongue so as to maintain aclear region between the tongue and the hard palate while the first andsecond pressures are applied. In this case at least one of the first andsecond ports is usually disposed in a tongue constraint which constrainsthe tongue. In addition a seal may be created between the soft palate,the tongue and/or a portion of the tongue constraint when the negativepressure is applied such that the airway is substantially fluidlyisolated from the first and second ports.

In a particular embodiment at least one of the first and secondpressures is positive pressure. The positive pressure may be appliedthrough the first port, the first port being positioned to apply thepositive pressure to the airway. Negative pressure may be appliedthrough the second port within the oral cavity while the positivepressure is applied to the airway. The second port is preferablysubstantially fluidly isolated from the airway after the negativepressure is applied.

In a further aspect of the invention, an apparatus for improving airwaypatency comprises an oral device positionable in a patient's oral cavityand having a tongue constraint for constraining a medial surface of thepatient's tongue in a position spaced apart from the patient's hardpalate. In addition, a continuous vacuum flow path is maintained fromthe patient's lips to the patient's soft palate, the oral device beingconfigured to maintain a seal between the soft palate and one or both ofthe tongue and the oral device when vacuum is applied through the vacuumflow path such that the airway is substantially fluidly isolated fromthe vacuum flow path. The oral device will mechanically enforce thevacuum flow path to ensure it is continuous from the front of the oralcavity to the soft palate; in some embodiments, the device itselfengages tissue along substantially all or a majority of the vacuum flowpath to keep it open; in other embodiments, the device engages tissue atleast along a posterior portion of the vacuum flow path, particularly inthe medial region of the tongue and posterior thereof, in a manner whichmaintains the patency of the entire vacuum flow path.

The tongue constraint will engage and constrain the tongue over an areaselected so that the tongue cannot be drawn upward into contact with thehard palate when the vacuum is applied such that the vacuum flow pathbecomes obstructed. This usually requires that the tongue be engaged inan area substantially posterior to its anterior tip. In mostembodiments, the tongue constraint engages the medial surface at a pointat least about ⅓ of the distance from an anterior tip of the tongue to aposterior end of the tongue. Preferably, the tongue constraint engagesthe medial surface at a point posterior to the midpoint between theanterior and posterior ends of the hard palate. The tongue constraintmay engage the tongue as far back as 20-25 mm posterior to the posteriorend of the hard palate where it joins to the soft palate. In addition,the tongue constraint will preferably have a shape and size adapted toengage and constrain at least a majority of the width of the tongue. Aposterior portion of the oral device, either part of the tongueconstraint or another component, may be configured to engage the softpalate when vacuum is applied. A smooth surface facing toward the softpalate is preferably provided on the posterior side of the oral devicewhich atraumatically engages the soft palate as it is drawn forward bythe vacuum.

In preferred embodiments, the vacuum flow path comprises a clear regionformed between the tongue and the hard palate. The vacuum flow path mayalso comprise a vacuum lumen integral with or coupled to the oraldevice. A delivery lumen may also be coupled to the oral device fordelivering positive pressure to the airway. A pressure sensor, oximetrysensor, and/or various other sensors may also be coupled to the oraldevice. The clear region will be in fluid communication with the softpalate through an opening facing away from the tongue so as to remainunblocked by the tongue when vacuum is applied. Preferably, the openingis disposed over or posterior to the medial region of the tongue,preferably being posterior to the midpoint between the anterior andposterior ends of the hard palate. Further, the opening is preferablyfacing in a direction generally toward the soft palate so as to applyvacuum directly to the soft palate. The oral device may also include oneor more inferior ports in communication with the vacuum flow path andconfigured to apply vacuum to a superior surface of the tongue, and/orlateral ports configured to apply vacuum to a lateral surface of thetongue and/or other posterior oral tissues.

The apparatus may also include one or more inferior ports incommunication with a vacuum lumen fluidly separate from the vacuum flowpath, such that vacuum may be exerted on the tongue independently fromthat exerted on the soft palate.

Usually the apparatus will include a lip seal for sealing the patient'slips to inhibit leaks into the oral cavity. The lip seal may comprise asealing structure positionable between the lips and the teeth, betweenthe upper and lower lips, or along the lips outside the oral cavity.

The apparatus may include a jaw engagement structure coupled to the oraldevice adapted to maintain the patient's jaw in a position selected tohelp keep the airway open. The jaw engagement structure may comprise atab on the oral device adapted to engage the patient's lower teeth tomaintain the lower jaw in an anterior position. The jaw engagementstructure may alternatively comprise a spacer disposed on the oraldevice and positionable between the patient's upper and lower teeth tomaintain the jaw in an open position.

The oral device will typically comprise an anchor structure adapted tomaintain the position of the oral device within the oral cavity. Theanchor structure may comprise a bite structure having channels adaptedto receive one or both of the patient's upper or lower teeth.Preferably, the tongue constraint comprises a plate having a width atleast about ½ the width of the tongue. The plate may have lateral edgesextending from an anterior to a posterior end thereof. In order toprovide rigidity to the plate and minimize deflection, at least aposterior portion of the lateral edges are fixed to the anchorstructure, usually in the region of the patient's molars. In preferredembodiments, the plate continuously spans substantially the entiredistance between the patient's molars, and is fixed on its lateral edgesto a bite structure held by the molars.

In yet another aspect of the invention, an oral device for improvingpatency of a patient's airway comprises a tongue constraint positionablein an oral cavity and adapted to engage a medial surface of a tongue andconstrain the medial surface in a position spaced-apart from a hardpalate so as to create a clear region therebetween, the clear regionbeing in communication with a soft palate through a posterior openingfacing in a posterior direction toward the soft palate; and means forconveying a vacuum to the clear region while the tongue constraintengages the tongue such that the soft palate is held in a position inwhich the airway is at least partially open, wherein the posterioropening is configured to remain unobstructed by the tongue when thenegative pressure is applied. Usually the tongue constraint willconstrain the medial surface at a point lying at least about ⅓ of theway from an anterior tip of the tongue to a posterior end of the tongue,and preferably posterior to the midpoint between the anterior andposterior ends of the hard palate. The posterior opening is preferablydisposed over or posterior to the medial region of the tongue,preferably being posterior to the midpoint between the anterior andposterior ends of the hard palate.

The posterior opening preferably lies in a first plane which is disposedat an angle of about 45-180 degrees, more preferably about 75-135degrees in the superior direction relative to the occlusal plane, theocclusal plane being a plane of contact between the patient's lowerteeth and the patient's upper teeth when the patient bites the teethtogether, or a plane containing the inferior surface of a bite structureon the oral device configured to fit between the upper and lower teeth.With this superior-facing and/or posterior-facing orientation, theposterior opening is configured to apply negative pressure to at leastthe upper portion of the soft palate when the airway is unobstructed,the upper portion being the superior portion of the soft palate havingan upper end joined to the hard palate. The posterior opening may bebounded on an inferior side by the tongue constraint and on a superiorside by the patient's hard or soft palate. Alternatively, the posterioropening may lie in a wall of the tongue constraint which is separatefrom that portion of the tongue constraint that engages the tongue. Forexample, the tongue constraint may have superior and inferior wallsenclosing a hollow interior chamber, wherein the inferior wall engagesthe tongue and the posterior opening is in the superior wall.Alternatively the tongue constraint may have a plate that engages thetongue, and the posterior opening may be in a posterior wall or landingpad which extends in a superior direction from a posterior edge of theplate and is configured to atraumatically engage the soft palate.

In some embodiments, the clear region is further in communication withat least one inferior port in the tongue constraint facing toward thetongue. The tongue constraint is preferably adapted to maintain the softpalate in engagement with one or both of the tongue and the tongueconstraint when vacuum is conveyed to the clear region to create a sealwhich substantially fluidly isolates the airway from the clear region.Usually, the tongue constraint is configured such that fluid within theclear region is in direct contact with an inferior surface of the hardpalate.

The means for conveying the vacuum will typically comprise at least onevacuum lumen coupled to or integral with the tongue constraint. Themeans for conveying a vacuum may also comprise a plenum network coupledto or integral with the tongue constraint. The vacuum lumen or theplenum network may be formed by one or more hollow regions, passages, orchambers within the tongue constraint or in a bite structure associatedtherewith. Such a vacuum lumen or plenum network may route the vacuumflow path in a manner that avoids the region between the anteriorportion of the tongue and hard palate by routing the vacuum lumen aroundthe outside of the teeth, through the bite line, around the lateraledges of the tongue, or below the tongue. With such configurations, theanterior portion of the tongue may contact the hard palate withoutaffecting vacuum delivery to the soft palate. The vacuum lumen or plenumnetwork may alternatively or additionally extend down at least onelateral side of the tongue.

A pressure lumen may also be coupled to the tongue constraint fordelivering fluid under positive pressure to the airway or other regionsof the oral cavity. Delivering positive pressure fluid to the oralcavity may facilitate clearance of saliva, while delivering positivepressure air to the airway may improve the pressure gradient thatimproves airway patency.

The oral device may also comprise an anchor structure coupled to orintegral with the tongue constraint. The anchor structure may include abite structure positionable between the upper and lower teeth, the bitestructure typically having tooth-receiving channels which receive theteeth. The anchor structure may alternatively or additionally include ahard palate engagement surface positionable against the hard palate tohold the tongue constraint in position.

The oral device will usually include a lip seal positionable along thepatient's lips to help seal the oral cavity when vacuum is applied. Thelip seal may be configured for positioning between the lips and teethwithin the oral cavity, between the upper and lower lips, or along theoutside of the lips external to the oral cavity.

The oral device may further include a pressure sensor coupled to thetongue constraint for monitoring pressure in the oral cavity, anoximetry sensor coupled to the tongue constraint for monitoring thepatient's blood oxygen level, or any of a variety of other sensors formonitoring various other conditions.

The oral device may be configured to maintain the patient's upper and/orlower jaws in a desired position other than their normal restingpositions. The oral device may comprise a jaw engagement structurecoupled to the tongue constraint and adapted to maintain the patient'sjaw in a position selected to help keep the airway open. The jawengagement structure may comprise a tab on the oral device adapted toengage the patient's lower teeth to maintain the lower jaw in ananterior position. The jaw engagement structure may alternativelycomprise a spacer disposed on the oral device and positionable betweenthe patient's upper and lower teeth to maintain the jaw in an openposition.

A posterior portion of the oral device may be configured to engage thesoft palate when vacuum is applied. The posterior portion will usuallycomprise an atraumatic surface against which the soft palate may bedrawn. In a particular embodiment, the oral device may include a softpad on a posterior surface of the tongue constraint configured to engagethe soft palate. A soft pad may also be provided on an inferior surfaceof the tongue constraint configured to engage the tongue.

In an alternative configuration the tongue constraint is movably coupledto the anchor structure to allow the tongue constraint to move withinthe oral cavity to reposition the tongue and/or soft palate therein. Thetongue constraint may be pivotally coupled, slidably coupled, orotherwise movably coupled to the anchor structure. Preferably the tongueconstraint will have vacuum ports in communication with the vacuumapplying means to allow the tongue constraint to adhere to the tongue.

The oral device may further include a soft palate landing pad coupled toor integral with the tongue constraint, the soft palate landing padhaving a posterior surface adapted to engage the soft palate when thesoft palate is in a position in which the airway patency is improved. Insome embodiments the soft palate landing pad is movably coupled to thetongue constraint. The soft palate landing pad may also include at leastone posterior port adapted to convey a vacuum toward the soft palate.Usually the posterior surface is disposed at an angle of about 45-180degrees, more preferably about 60-135 degrees relative to an occlusalplane defined by a plane of contact between the patient's upper andlower teeth. In exemplary embodiments, the soft palate landing padcomprises a wall extending superiorly from a posterior edge of thetongue constraint.

In still another aspect of the invention, an apparatus for improvingairway patency comprises an oral device positionable in an oral cavity;a first port coupled to or integral with the oral device in a firstlocation; a second port coupled to or integral with the oral device in asecond location; means for applying a first pressure through the firstport; and means for applying a second pressure through the second port,the second pressure being different than the first pressure; wherein theoral device is configured such that application of the first and secondpressures through the first and second ports in the oral cavity holdsthe tongue and the soft palate in a position in which the airway is atleast partially open.

In preferred embodiments the oral device comprises a tongue constraintpositionable in the oral cavity and adapted to engage a superior surfaceof a tongue and constrain at least a portion of the tongue in a positionspaced-apart from a posterior portion of the hard palate. In someembodiments the first and second ports are movable relative to eachother within the oral cavity. Preferably, the first and second ports areadapted to maintain the soft palate in sealing engagement with thetongue and/or the oral device such that the oral cavity is substantiallyfluidly isolated from the airway.

The means for applying the first pressure may comprise a first pump andthe means for applying the second pressure may comprise a second pump.“Pump” is intended to mean a negative pressure generator, a positivepressure generator, a hand pump, syringe, suction cup, or other means ofcreating positive or negative pressure. Alternatively, the means forapplying the first pressure may comprise a first pump and a firstpressure regulator, and the means for applying the second pressure maycomprise the first pump and a second pressure regulator.

Usually the second port is configured to apply the second pressure tothe soft palate, while the first port is configured to apply the firstpressure to the tongue.

The oral device may further comprise an anchor structure adapted toanchor the oral device within the oral cavity. In some embodiments thefirst port is immovable relative to the anchor structure, while thesecond port is movable relative the anchor structure. In specificembodiments the second port is disposed in a landing pad movably coupledto the anchor structure.

The means for applying a first pressure may be adapted to apply positivepressure through the first port. In such cases, the first port isusually adapted to apply the positive pressure to the patient's airway.For example, the first port may be disposed in a conduit adapted toextend posteriorly from the oral device into the patient's airway.

In a further aspect, a system according to the invention comprises anoral device positionable in a patient's oral cavity and adapted tocreate a continuous vacuum flow path from the patient's lips to thepatient's soft palate; a vacuum source in fluid communication with thevacuum flow path; and a liquid collector in communication with thevacuum flow path adapted to collect liquid aspirated from the oralcavity.

Usually a conduit such as a tube will be connected between the oraldevice and the liquid collector. The vacuum source is preferably adaptedto maintain substantially the same negative pressure in the vacuum flowpath when aspirated liquid is present in the conduit between the vacuumflow path to the vacuum source as when no liquid is present therein. Insuch embodiments the system will usually include a pressure sensor incommunication with the oral cavity. The vacuum source may comprise apump and a controller, the pressure sensor being coupled to thecontroller such that the controller regulates the pump in response tosignals received from the pressure sensor. The system may also include apressure tube coupled to the oral device and having a port incommunication with the oral cavity, the pressure sensor being incommunication with the pressure tube. Alternatively the pressure sensoris attached to the oral device and further comprises a lead coupledthereto for conveying electrical signals from the sensor.

A vacuum tube may be coupled to the oral device in communication withthe vacuum flow path, the vacuum tube being in fluid communication withthe vacuum source. The weight of any aspirated liquid in the vacuum tubecan create pressure offsets depending on the orientation of the tube andthe amount of liquid in the tube. In order to facilitate the flow ofaspirated liquid to the liquid collector, the system may include a ventin fluid connection with the vacuum flow path preferably in or near theoral cavity. In one embodiment, the vacuum tube has a vent hole thereinthrough which air may flow into the vacuum flow path. In anotherembodiment, a vent tube may be connected to the oral device or thevacuum tube in communication with the vacuum flow path, the vent tubehaving an opening to allow the introduction of a small amount of airinto the vacuum flow path. By using this venting technique to clear theliquid, the pressure-offsetting effects of liquid present in the vacuumtube will be minimized.

The liquid collector preferably comprises an airtight space having aninlet and an outlet, the vacuum tube being connected to the inlet, theoutlet being fluidly connected to the vacuum source. The liquidcollector collects the aspirated liquid in the airtight space up to amaximum level, and the inlet and the outlet are usually separated fromthe maximum level by a liquid-free space. The vacuum is thereby conveyedfrom the outlet to the inlet through the liquid-free space.

The oral device usually comprises a tongue constraint adapted tomaintain at least a medial portion of the tongue in a position spacedapart from the patient's hard palate so as to maintain a clear regiontherebetween. Preferably the oral device is adapted to maintain the softpalate in sealing engagement with the tongue and/or the oral device sothat airway is more patent and substantially fluidly isolated from thevacuum flow path.

In yet another aspect, a system according to the invention comprises anoral device positionable in a patient's oral cavity and adapted tomaintain a continuous vacuum flow path from the patient's lips to thepatient's soft palate and substantially seal the patient's airway fromthe vacuum flow path; a vacuum source in fluid communication with thevacuum flow path; and a sensor for detecting at least one conditionwithin the oral cavity.

In a preferred embodiment, the system will further include a controllercoupled to the sensor and the vacuum source for controlling the vacuumsource in response to signals generated by the sensor. In one embodimentthe sensor comprises a pressure sensor and the controller is adapted toautomatically regulate the vacuum source so as to maintain asubstantially constant negative pressure in the oral cavity.Alternatively, pressure readings from the pressure sensor are used toregulate the vacuum source so as to maintain the pressure in the oralcavity at one or more desired levels.

The system may further include a recording device coupled to the sensorand adapted to record data received from the sensor over a time period.The recording device may comprise a memory device such as a read-onlymemory device, random-access memory device, or removable memory devicesuch as an optical disk or flash drive. Usually the system will furtherinclude a computer in communication with the memory device, a displayadapted to display information from the memory device to the user and auser input device adapted to transmit information from the user to thecomputer. Preferably, the time period is selectable by the user to beany of a plurality of times periods.

In most embodiments the sensor is attached to the oral device so as tobe positionable in the oral cavity. In other embodiments the systemfurther includes a tube attached to the oral device and having a portlocated in the oral cavity when the oral device is positioned therein,the sensor being in communication with the tube outside the oral cavity.

The sensor may comprise a pressure sensor adapted to detect pressure inthe patient's oral cavity, an oximetry sensor adapted to detect oxygenlevels in the oral cavity or in the patient's blood or tissue, animpedance sensor adapted to detect contact between the oral device andtissues in the oral cavity, an accelerometer adapted to detect theorientation of the patient's head, a piezoelectric sensor for detectinga sound selected from breathing, snoring, teeth grinding, or heartbeat,a moisture sensor to detect moisture in the oral cavity, a flow sensorfor detecting air flows or leaks in the oral cavity, or a temperaturesensor. In one configuration the temperature sensor is adapted to detectthe temperature of air in or adjacent to the airway. For example, thetemperature sensor may be mounted to the oral device so that when theoral device is in place, the sensor is positioned just below thenostrils so as to sense air temperature just outside the nasal airway,allowing the patient's rate of breathing to be monitored. The system mayfurther include at least a second sensor for monitoring a secondcondition in the oral cavity. The second sensor is preferably coupled tothe oral device along with the first sensor.

The system may further include a transmission device for electronicallytransmitting information from the recording device to an externaldevice. The transmission device may be a modem, a docking station, acable connector, a wireless transmitter, or other type of datatransmission device.

Preferably, the oral device is adapted to maintain the soft palate insealing engagement with the tongue and/or the oral device such that theairway is substantially fluidly isolated from the vacuum flow path. Insuch cases the sensor may be adapted to monitor whether the airway isfluidly isolated from the vacuum flow path. For example the sensor maybe a pressure sensor for monitoring pressure in the oral cavity, or aflow sensor for monitoring flow rate through the vacuum flow path.

The system may further include an alarm adapted to provide a visual oraudible signal in response to data received from the sensor. Forexample, if pressure or oxygen level in the oral cavity is at anundesirable level, the system may provide an audible alarm to wake thepatient and/or notify them that a change is required, e.g. ensuring theoral device is positioned properly, repositioning the patient's head,etc.

Additionally, the system may include a liquid collector in communicationwith the vacuum source for collecting liquid aspirated from the oralcavity. Usually a vent will be provided in communication with the vacuumflow path in or near the oral cavity so as to allow the introduction ofa small amount of air into the vacuum flow path such that aspiratedliquid moves quickly from the vacuum flow path to the liquid collector.Preferably, the vacuum source is adapted to automatically maintain adesired level of negative pressure in the oral cavity as liquid is beingaspirated. In such embodiments the sensor may comprise a pressure sensorfor monitoring pressure in the oral cavity.

A further understanding of the nature and advantages of the inventionmay be gained by reference to the following detailed description takenin conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the relevant anatomy of the nasal and oral cavities.

FIG. 2A illustrates a first embodiment of an oral device constructed inaccordance with the principles of the present invention.

FIG. 2B illustrates use of the device of FIG. 2A for inhibition of OSAwhen placed in an oral cavity of a patient.

FIGS. 3A-3C illustrate a second embodiment of an oral device constructedin accordance with the principles of the present invention, where FIG.3A is a perspective view, FIG. 3B is a top view, and FIG. 3C is a bottomview.

FIG. 4 is a perspective view of a third embodiment of an oral deviceconstructed in accordance with the principles of the present invention.

FIG. 5 is a top view of a fourth embodiment of an oral deviceconstructed in accordance with the principles of the present invention.

FIGS. 6A-6C illustrate a fifth embodiment of an oral device constructedin accordance with the principles of the present invention, where FIG.6A is a perspective view, FIG. 6B is a side view, and FIG. 6C is across-sectional view taken along line 6C-6C of FIG. 6B.

FIGS. 6D and 6E illustrate use of the device of FIGS. 6A-6C forinhibiting OSA when placed in an oral cavity of a patient, where FIG. 6Dis a side cross-sectional view and FIG. 6E is a sectional view takenalong line 6E-6E in FIG. 6D.

FIGS. 7A-7C illustrate a sixth embodiment of an oral device constructedin accordance with the principles of the present invention, where FIG.7A is a perspective view, FIG. 7B is a side view, and FIG. 7C is across-sectional view taken along line 7C-7C in FIG. 7B.

FIGS. 7D-7F illustrate use of the device of FIG. 7A-7C for inhibitingOSA when placed in the oral cavity of a patient.

FIGS. 8A-8D illustrate a seventh embodiment of an oral deviceconstructed in accordance with the principles of the present invention,where FIG. 8A is a perspective view, FIG. 8B is a detailed view of anadjustable tongue constraint, FIG. 8C is a side view of the device, andFIG. 8D is a cross-sectional view taken along lines 8D-8D of FIGS. 8Aand 8C.

FIGS. 9A-9C illustrate an eighth embodiment of an oral deviceconstructed in accordance with the principles of the present invention,with FIG. 9A being an perspective view, FIG. 9B being a side view, andFIG. 9C being a cross-sectional view taken along line 9C-9C of FIG. 9B.

FIGS. 10A-10C illustrate a ninth embodiment of an oral deviceconstructed in accordance with the principles of the present invention,where FIG. 10A is a perspective view, FIG. 10B is a top view, and FIG.10C is a cross-sectional view taken along line 10C-10C of FIG. 10B.

FIG. 10D illustrates use of the device of FIGS. 10A-10C for inhibitingOSA when placed in an oral cavity of a patient.

FIG. 11 is a perspective view illustrating a patient asleep at nightusing the apparatus of the present invention.

FIG. 12 is a schematic illustration of a control system or console foruse in aspirating a negative pressure in the oral devices of the presentinvention.

FIGS. 13A-13C illustrate a mechanical or manual vacuum generator thatcan be used with any of the oral devices of the present invention, whereFIG. 13A illustrates the manual vacuum generator attached to the oraldevice of FIG. 4, with FIG. 13B showing the device in use with a salivacollector, and FIG. 13C showing the internal components of the device.

FIGS. 14A-14D are top, oblique, front and side cross-sectional views,respectively of an oral device according to the invention in a furtherembodiment thereof.

FIG. 14E is a side cross-sectional view of the oral device of FIGS.14A-D positioned in a patient's oral cavity.

FIGS. 15A-E are top, front oblique, rear oblique, front, and sidecross-sectional views, respectively, of an oral device according to theinvention still another embodiment thereof, in which the lip seal isremoved for clarity.

FIGS. 16A-16C are top, front and side cross-sectional views,respectively of an oral device according to the invention in stillanother embodiment thereof, in which the lip seal is removed forclarity.

FIGS. 17A-17D are top cutaway, oblique, front, and side cross-sectionalviews, respectively of an oral device according to the invention instill another embodiment thereof, in which the lip seal is removed forclarity.

FIGS. 18A-18C are oblique, front, and side cross-sectional views,respectively of an oral device according to the invention in stillanother embodiment thereof, in which the lip seal is removed forclarity.

FIGS. 19A-19D are top cutaway, oblique, front and side cross-sectionalviews, respectively of an oral device according to the invention instill another embodiment thereof, in which the lip seal is removed forclarity.

FIG. 19E is a schematic illustration of a system for applying differentpressures to different regions of the oral cavity shown with the oraldevice of FIGS. 19A-D.

FIGS. 20A-20C are top, oblique and side cross-sectional views,respectively of an oral device according to the invention in stillanother embodiment thereof, in which the lip seal is removed forclarity.

FIGS. 21A-21B are oblique and side cross-sectional views, respectivelyof an oral device according to the invention in still another embodimentthereof, in which the lip seal is removed for clarity.

FIGS. 22 and 22B are top and side cross-sectional views, respectively ofan oral device according to the invention in still another embodimentthereof, in which the lip seal is removed for clarity.

FIG. 22A is a side partial cross-section taken along line A-A in FIG.22.

FIGS. 23A-23B are oblique and side cross-sectional views, respectivelyof an oral device according to the invention in still another embodimentthereof, in which the lip seal is removed for clarity.

FIG. 23C is a schematic illustration of a system for deliveringdifferent pressures to different regions of the oral cavity, shown withthe oral device of FIGS. 23A-B.

FIGS. 24A-24C are oblique, top, and side cross-sectional views,respectively of an oral device according to the invention in stillanother embodiment thereof.

FIG. 25 is a schematic view of a system according to the invention in afurther embodiment thereof.

FIG. 26 is a schematic view of a system according to the invention instill another embodiment thereof.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the anatomy of the oral and nasal cavities relevantto obstructive sleep apnea (OSA) and the placement of the devices of thepresent invention will be described. The upper teeth UT of the patientare anchored in the hard palate HP, and the lower teeth LT are anchoredin the lower jaw or mandible LJ. The soft palate SP extends in arearward or posterior and inferior direction from the hard palate, andtogether the hard palate and soft palate divide the nasal airway NA fromthe oral cavity OC. The lower extent of the oral cavity is largelydefined by the upper surface of the tongue T in this view, and it willbe appreciated that both the soft palate SP and the tongue are mobilestructures capable of movement between the positions shown in full lineand broken line in FIG. 1. A nasal airway NA extends inferiorly into thepharynx P which defines the airway generally behind the soft palate SPand the tongue T. The regions on the tongue and soft palate shown with aheavy dashed line are the areas responsible for the gag reflex GR.

Obstructive sleep apnea occurs when either the soft palate, the tongueor both move in a posterior direction so that they contact the rear orposterior surface of the pharynx P. The posterior motion of the softpalate and/or tongue may also reduce the size of the airway withoutcontacting the pharynx P causing a partial blockage. The temporaryblockage of the airway behind the soft palate and tongue will cause thedisrupted breathing pattern characteristic of OSA and usually associatedwith snoring.

Referring now to FIGS. 2A and 2B, a first exemplary oral device 10constructed in accordance with the principles of the present inventioncomprises an anchor structure 12, a tongue constraint 14, and a plenumstructure 16 adapted to aspirate the oral cavity and apply a negativepressure therein while the anchor structure is held in the patient'smouth. The anchor structure 12 includes a bite structure 20 having upperand lower tooth-receiving channels 22 and 24, respectively, as best seenin FIG. 2B. The portions of upper and lower tooth-receiving channels 22and 24 that contact the lips help to create a seal which inhibits entryof air into the oral cavity. The tongue constraint 14 comprises aJ-shaped tube 26 which passes through or is otherwise coupled to theanchor structure 20 so that a posterior end 28 of the tube lies over aposterior end of the medial region of the tongue, as best seen in FIG.2B. Optionally, the tongue constraint 14 may further include a tongueretraction plate 30 which extends over the medial region of the tongueto help constrain the tongue inferiorly to create a clear or open region32 over the tongue and beneath the soft palate, as best seen in FIG. 2B.

The plenum structure 16 is partly formed within the J-shaped tube 26 ofthe tongue constraint and partly provided by a separate lateral tonguevacuum tube 34. The vacuum tube 34 has a Y-shaped geometry with legs 36and 38 extending laterally and generally inferiorly on either side ofthe tongue. Legs 36 and 38 serve to create negative pressure in portionsof the oral cavity that may otherwise be sealed off by the compliantmouth tissues, thereby helping to urge the tongue and soft palateforward. Both the J-shaped tube 26 and the tongue vacuum tube 34 have aplurality of vacuum ports 40 and 42, respectively, distributed alongtheir lengths. Typically, the tubes 26 and 34 will have inside lumendiameters in the range from 0.5 mm to 5 mm, with ports having widths inthe range from 0.5 mm to 10 mm, often having an oval shape asillustrated, but optionally having other shapes. By having multiplepoints spaced throughout the oral cavity, particularly within theposterior region of the oral cavity, the ability to provide a continuousaspiration to maintain the desired level of negative pressure or vacuumis greatly enhanced. It will be appreciated that even if certain ones ofthe vacuum ports 40 and 42 become blocked, others will remain open toexpose the clear region created by the tongue retraction plate 30 to thedesired pressure. As can be seen in FIG. 2B, vacuum tube 26, plenumstructure 16, and clear region 32 provide a continuous vacuum flow pathfrom the patient's lips to the soft palate through which vacuum may beapplied. By applying the desired vacuum or negative pressure, the softpalate SP will be drawn inferiorly and anteriorly against the posteriorregion of the tongue T, generally forming a seal which substantiallyfluidly isolates the airway from the vacuum flow path and permits thenegative pressure to draw the soft palate and tongue anteriorly to openup the airway behind the soft palate and tongue adjacent the pharynx P.

Referring now to FIGS. 3A-3C, a second exemplary embodiment of the oraldevice 50 will be described. The oral device 50 includes generally thesame components as the oral device 10 with an anchor structure 52 beinggenerally identical to the anchor structure 12. A tongue constraint 54is similar to tongue constraint 14, except that it is formed from a tube56 having an oval tubular structure 58 at its proximal end. The ovaltube 58 allows the vacuum or negative pressure connection to extendthrough both sides of the tube, rather than terminating at one end, aswith the J-shaped tube 26 of device 10. This provides for more robustoperation by allowing negative pressure to be applied even if the lumenof oval tube 58 becomes clogged. Oral device 50 also includes a plenumstructure comprising a tube 62 with inferiorly oriented arms 64 and 66which is generally similar to the lateral vacuum tube structure 34 oforal device 10. The arms 64 and 66, however, are curved rather thanstraight as in the earlier embodiment. Oral device 50 generally providesfor more open space 67 on the anterior side of the tongue retractionplate 68.

FIG. 4 is a further variation of an oral device 70 which is almostidentical to device 50, except that a tongue constraint structure 72 hasan arcuate or curved lateral cross section in contrast to the straightcross section of tongue constraints 54 and 14 in oral devices 50 and 10,respectively. The arcuate shape of the tongue constraint structure 72may improve the comfort of the device by allowing for a more naturaltongue position. The palate and the tongue naturally take on a similardomed shape.

FIG. 5 is a further variation of an oral device 74 which is almostidentical to device 50 with tube 76 being generally identical to tube 56and tube 78 generally being identical to tube 62. Oral device 74 alsoincludes tubes 80 and 82 which generally follow the paths of tubes 76and 78, respectively. Tube 82 bifurcates into arms 84 and 86 in asimilar manner as arms 64 and 66. Ports 88 and 90 are in fluidcommunication with tubes 82 and 80, respectively. Tubes 80 and 82 can bethereby be used to monitor the negative pressure in the oral cavity atthe locations of ports 88 and 90 by connecting tubes 80 and 82 topressure sensors. In addition fluids such as humid air or warmed salinemay be introduced via tubes 80 and 82 and ports 88 and 90 in order toenhance patient comfort by moistening the oral cavity or by helping toaspirate fluids such as saliva that may have collected in the oralcavity.

Referring now to FIGS. 6A-6E6D, a third exemplary embodiment of the oraldevice 92 will be described. The oral device 92 generally providessimilar components as the oral device 70. An anchor structure 96includes bite structure 98 which is configured to be held between thepatient's upper and lower teeth. Bite structure 98 does not includetooth-receiving channels and is open at the front allowing the frontteeth to overlap, thus improving patient comfort by minimizing the bulkof the device and allowing the mouth to close more than oral device 70allows. Instead of relying on tubes to convey the negative pressure,tongue constraint structure 94 is hollow and includes one or more vacuumports 99, thereby reducing the overall size and bulk of the tongueconstraint structure. Portions of bite structure 98 may be hollow andused to convey the negative pressure. A tubular structure 100 mayadditionally be employed to convey the negative pressure. A lip sealstructure 102 facilitates creating a seal at the mouth by contacting theinner surface of the lips proximate the mouth opening. The lip sealstructure 102 may also be hollow in order to convey negative pressure tovacuum ports 104 which are positioned to help ensure that negativepressure is well-distributed proximate the lips, thus providing forimproved lip sealing forces. One or more lateral tongue structures 108may be flexible and also hollow in order to convey negative pressure tovacuum ports 110 which are positioned to enhance the distribution ofnegative pressure into the oral spaces lateral to the tongue. A vacuumplenum 105 may thusly comprise contiguous hollow portions of lip sealstructure 102, tubular structure 100, bite structure 98, tongueconstraint structure 94, lateral tongue structures 108, and a vacuumtube 109 that is connected to a source of negative pressure. Optionally,lip seal protrusion 106 may enhance the formation of a seal at the lipsby concentrating lip contact forces at the protrusion. Optionally, asensor 112 such as a pressure sensor with connecting cable 114 may bemounted on tongue constraint structure 94 or on any other part of thedevice for example to monitor the pressures developed in the oralcavity.

Referring now to FIGS. 7A-7F, an oral device 142 that employs a portablevacuum source 120 which can be used with the vacuum plenum of any of theoral devices described is illustrated. Portable vacuum source 120includes a connection port or tube 122 which can be connected to thevacuum plenums of any of the previously or subsequently described oraldevices. The portable vacuum source 120 includes battery 124, controlelectronics 126, a motor 128, and a pump 130, as best seen in FIG. 7E.Connector line 132 may be provided to allow the electronics 126 to beconnected to sensors or other components on the oral device. Forexample, the oral device may be provided with an electric heater 134 toprovide warmth that may improve patient comfort. Optionally, salivacollection reservoir 136 may be connected to the portable vacuum source120 by a flexible connecting tube 138, as best seen in FIG. 7F. Thesaliva collection reservoir 136 will have a porous cover 140 which willallow air to bleed while retaining the saliva in the reservoir. Insteadof the discrete vacuum ports that are employed in the previouslydescribed oral devices, oral device 142 employs a porous material 144such as porous polyethylene to distribute the negative pressure into theoral cavity. Porous material 144 has small pores which act to filter outparticulates that could collect and clog the vacuum tubes. Porousmaterial 144 also has a large number of pores and a large surface areaof pores which help to maximize the spatial extent of negative pressurewithin the oral cavity.

Referring now to FIGS. 8A-8D, an oral device 146 which is very similarto oral device 92 except that it employs an adjustable tongue constraintstructure 148 which can be used with any of the oral devices describedis illustrated. Adjustable tongue constraint structure 148 has threepairs of through holes 150 at each side. Each pair of through holes 150may be engaged with a pair of the four protrusions 152 which extend fromeach of the bite structures 154. It can be appreciated that adjustabletongue constraint structure 148 may be moved superiorly, inferiorly,anteriorly, and posteriorly by engaging various pairs of holes 150 withappropriate pairs of protrusions 152 as best shown in FIG. 8A. Suchadjustability facilitates the fitting of oral device 146 to the anatomyof a particular patient. Adjustable tongue constraint structure 148 ishollow and is connected to vacuum tube 154 by means of flexible tube 156and tubular structure 158. Bite structures 154 may also be hollow inorder to convey negative pressure as with oral device 92.

Referring now to FIGS. 9A-9C, an oral device 160 which is very similarto oral device 92 except that it employs a flexing tongue constraintstructure 162 which can be used with any of the oral devices describedis illustrated. Flexing tongue constraint structure 162 is very similarto tongue constraint structure 94 except that a window 164 is formed ateach lateral end of the flexing tongue constraint structure 162. Windows164 are sized to create a pair of narrow flexure arms 166 at eachlateral end of flexing tongue constraint structure 162. Flexure arms 166are fabricated from a flexible material such as polyurethane so thatflexing tongue constraint structure 162 is allowed to flex anteriorlywhen the portion of the tongue it contacts is urged anteriorly by thenegative pressure in the oral cavity. This anterior motion of flexingtongue constraint structure 162, best seen in FIG. 9B, may facilitatefurther anterior motion of the tongue and soft palate as compared withoral device 92, thereby improving the ability of oral device 160 to openthe airway. Because flexing tongue constraint structure 162 and flexurearms 166 are hollow, negative pressures are conveyed in a very similarmanner as with oral device 92.

Referring now to FIGS. 10A-10D, an oral device 170 having an alternativeanchor structure 172 will be described. In all previous embodiments, theanchor structure of the oral device has been intended to be held betweenthe patient's teeth in order to provide a support for the tongueconstraint. That is, the anchor structure held between the patient'steeth is attached to the tongue constraint and transmits force tomaintain the tongue position through the anchor between the teeth. Inthe oral device 170, the anchor structure 172 has an upper surface 174which is configured to rest against the inferior surface of the palate,as best seen in FIG. 10D. A pair of depending sidewalls 176 and 178adjoin to a curved or arcuate tongue constraint 180 which includes anopen interior or plenum 182 having a plurality of ports 184 over itsupper surface.

Vacuum or negative pressure can be provided to the plenum 182 by aU-shaped tube 186 which is adapted to circumscribe the patient's teethTE, as best shown in FIG. 10B. It can be seen that the teeth can befully closed with the tube extending around the rear molars when theanchor structure 172 is positioned in the oral cavity, as shown in FIG.10D. A flexible tube 188 is connected to the vacuum supply tube 186through a lip seal structure 190, as shown in cross section in FIG. 10C.The lip seal structure 190 has a flat and tapered shape so the patient'supper and lower lips can conform to it thereby facilitating the seal inthe oral cavity as a vacuum or negative pressure is drawn through thedevice.

Referring now to FIG. 11, in addition to the portable battery poweredvacuum source described earlier, the oral devices of the presentinvention may receive the desired vacuum or negative pressure from atabletop unit 200 which can be operated off of house current and/orbattery power. The tabletop unit 200 may be connected to the oral device(within the patient's mouth in FIG. 11) through a relatively long,flexible, crush-resistant, small and lightweight connector tube 202. Thelong connector tube is convenient and allows the patient to sleepcomfortably in any position with minimal disruption.

The tabletop control unit 200 may comprise a number of internalcomponents, as best illustrated in FIG. 12. The tabletop control unitwill usually include a user interface 204. In order to generate thenegative pressure used by the oral devices described above and to reducethe accumulation of fluid within the mouth, one or more pumps 220,sensors 222 for flow, pressure, or the like and traps 224 will usuallybe provided. The traps 224 remove saliva and other substances from thetubing to prevent them from entering the pumps 220. The sensors 222 maybe used to determine if the device is operating and being appliedproperly. For example an air leak would generate higher than normal flowand the user could be alerted that there is a problem. Optionally valve232 may be provided for briefly allowing air to enter the device or oralcavity in order to facilitate aspiration of fluids that have collectedin the oral cavity or device. Optionally fluid source 214 and pump 206for providing moisture and a heater/cooler 216 for heating or coolingthe fluid, may be provided. Electronics and power control module 208will provide for the desired control functions of the unit. Optionally afeedback loop may be configured to monitor the pressure in the oralcavity for example as described above using tubes 80 and 82 connected toa pressure sensor 212 and to adjust the power of the one or more vacuumpumps 220 in order to maintain the desired level of negative pressure inthe oral cavity. Varying distributions of saliva in the tubing thatconnects the control unit 200 to the oral devices described above willcreate a pressure differential and such a feedback loop couldcontinually compensate for this varying differential. Optionally, a port210 may be provided for external connection of the control unit to acomputer or data distribution network. Each of these components may beconnected to the oral device through appropriate tubes, wires or otherconnectors 230.

Referring now to FIGS. 13A-13C, a mechanical vacuum generator 250 willbe described. The mechanical vacuum generator 250 includes a cylindricalbody 252, a plunger 254, and an attachment port or tube 256 which can befixedly or removably attached to the plenum structure of any of the oraldevices described previously. Shown in FIG. 13A, the mechanical vacuumgenerator 250 is connected to the oral device 70 of FIG. 4.

The mechanical vacuum generator 250 may be attached to a salivacollection reservoir 260 which may be generally the same as the salivacollection reservoir 136 described previously in FIGS. 7F and 7E. Ofcourse, other saliva-collecting or saliva-absorbing configurations maybe employed without departing from the scope of the invention.

The mechanical vacuum generator 250 includes a bellows 262 attached tothe plunger 254. A spring 264 is configured to urge the bellows to anexpanded volume configuration, i.e. to the left, as shown in FIG. 13C.Thus, when the patient depresses the plunger 254, the bellows 262 may becompressed to the right, which at the same time compresses spring 264.The spring will urge the bellows to open and draw a vacuum throughconnecting line 256, which is connected to the oral device. One-way flowvalves 272 and 274 permit saliva to pass into the cylindrical body 252where it collects. When the user depresses the plunger 254, the salivais expelled into the collection bag 260 through one-way valve 274.Plunger 254 may be depressed as often as necessary to maintain thedesired vacuum or negative pressure within the oral device.

A further embodiment of an oral device according to the invention isillustrated in FIGS. 14A-D. Oral device 280 has a tongue constraint 282with a bite structure 284 integrally formed with or fixed to the tongueconstraint 282 around its anterior and lateral edges. Similar toprevious embodiments, bite structure 284 has a U-shaped channel 286adapted to receive the upper teeth so as to anchor the oral device 280in the oral cavity. U-shaped channel has an outer wall 287 which extendssuperiorly to cover at least a portion of the upper teeth, and an innerwall 289 which may be shorter or optionally eliminated entirely. Outerwall 287 and/or inner way 289 may have a height to cover the upper teethentirely so as to inhibit leaks from the oral cavity posterior to theteeth.

Tongue constraint 282 comprises a curved or dome-shaped plate 288 havinga concave inferior surface adapted to engage the superior surface of thetongue to constrain at least a portion of the tongue in a positionspaced apart from the patient's hard palate, thereby creating a clearregion superior to plate 288 and inferior to the hard palate thatcontinuously extends from the posterior side of bite structure 284 tothe soft palate. In preferred embodiments, the superior surface oftongue constraint 282 is spaced apart from the patient's hard palate byat least about 0.5 mm. Tongue constraint 282 preferably has sufficientrigidity to constrain the tongue in a position-spaced apart from thehard palate. While some flexibility is possible, tongue constraint 282will have sufficient resilience and strength to overcome any deflectioncaused by movement of the tongue to return to an unbiased position inwhich the tongue is spaced apart from the hard palate. In order to applya distributed force across a broad area of the tongue, tongue constraint282 is preferably configured to engage at least ½ of the width of thetongue (in the lateral direction, left to right). In this embodiment,plate 288 of tongue constraint 282 spans the entire distance across theopen end of U-shaped bite structure 284 between the patient's left andright molars and is thus configured to engage substantially the entirewidth of the tongue.

As in previous embodiments, the plate 288 preferably engages the medialregion of the tongue so as not to contact the region of the tongue thattends to initiate the gag reflex. Plate 288 is preferably continuousthroughout the area circumscribed by bite structure 284 (except forvacuum ports 296, described below). Plate 288 will usually engage themedial surface of the tongue at a location that is at least about ⅓ ofthe way, more preferably at least about ½ of the way, from the anteriortip of the tongue to the posterior end of the tongue. Usually, plate 288engages the medial surface at a point posterior to the midpoint betweenthe anterior and posterior ends of the hard palate. Plate 288 may engagethe tongue as far back as or even beyond the posterior end of the hardpalate where it joins to the soft palate; however, plate 288 isconfigured to allow the soft palate to engage the posterior side ofplate 288 in a position in which the airway is at least partially open,so will usually not extend posteriorly more than about 20 mm beyond theposterior end of the hard palate HP, and preferably not more than about25 mm posteriorly beyond the normal location of the patient's secondmolars. If an imaginary cylinder were drawn between the patient'snasopharynx and laryngopharynx with diameter about the same as thelaryngopharynx, in preferred embodiments plate 288 would not intersectsuch a cylinder.

Plate 288 forms a soft palate landing pad 290 on its posterior sidehaving a posterior surface 292 which angles inferiorly and posteriorlyfrom the apex A of the dome-shaped plate 288. Soft palate landing pad290 is adapted to engage the soft palate when vacuum is applied throughthe oral device. Posterior surface 292 may be arcuate, spherical, planaror a combination thereof. In exemplary embodiments, as shown in FIG.14D, posterior surface 292 extends a length L of at least about 5 mmfrom the inferior surface 295 of bite structure 284, and posteriorsurface 292, or a plane P tangential with posterior surface 292, isdisposed at an angle α of at least about 45°, more preferably about60-135°, and most preferably about 90-135°, relative to a horizontalplane H containing an inferior surface 295 of the bite structure 284.Horizontal plane H is generally coplanar with the occlusal plane, theplane in which the upper and lower teeth meet when the patient bitestogether.

Plate 288 has a plurality of vacuum ports 296 extending entirely throughits thickness. Vacuum ports 296 are disposed in locations on plate 288selected to direct negative pressure (suction) within the clear regionsuperior to plate 288 against the superior surface of the tongue on theinferior side of plate 288. Various locations and arrangements arepossible, but in one embodiment vacuum ports 296 are disposed within acentral region of plate 288 which contacts the medial region of thetongue. In this embodiment vacuum ports 296 are arranged in a gridgenerally centered on apex A in a central portion of plate 288 andextending laterally in both directions to points adjacent to U-shapedchannel 286, with soft palate landing pad being free of vacuum ports.Optionally, vacuum ports 296 may also be provided on soft palate landingpad 290.

As an alternative to vacuum ports 296 shown, plate 288 may be made of aporous material to allow air to pass through it, such as a porouspolyethylene or other porous polymer. As a further alternative, plate288 may have very small or even microscopic holes created by laserdrilling, etching, or other suitable process throughout its entire areaor in a selected region or regions thereof.

A vacuum tube 298 is fixed to the surface of plate 288 and extendsanteriorly through plate 288 and bite structure 284 where it connects toan extension tube 300, which is connectable to a suction source such asa vacuum pump or portable vacuum source as described in earlierembodiments. Optionally, a detachable connector (not shown) may beconnected to the end of extension tube 300 to allow detachableconnection to a complementary connector (not shown) on a portable vacuumsource or a tube extending to the vacuum source. Vacuum tube 298preferably has a plurality of holes 302 on a sidewall thereof, and mayhave an open distal end 304, through which vacuum is applied to theclear space created superiorly of plate 288. Vacuum tube 298 may bestraight and located in the center of plate 288 as shown, oralternatively may have a variety of other configurations and locationson the oral device as described elsewhere herein. Vacuum tube 298 mayterminate at a point anterior to apex A as illustrated, or may extend toa point further posterior on the plate 288. As an alternative to thevacuum tube 298 illustrated, a vacuum lumen may be formed integrallywithin plate 288 with outlet ports in the superior surface and/orinferior surface of plate 288 in communication with the vacuum lumen.

Oral device 280 further includes a lip seal 306 configured to be placedbetween the teeth and lips to help inhibit air from leaking between thelips so as to maintain a seal in the oral cavity. Lip seal 306 maycomprise a flexible polymeric sheet slidably mounted over extension tube300 and fluidly sealed therewith. Lip seal 306 will have sufficientflexibility to conform to the shape of the user's teeth and lips so asto provide a substantially air-tight seal.

Referring to FIG. 14E, tongue constraint 282 preferably engages andconstrains a region of the tongue T which is at least in part posteriorto the midpoint MP between the anterior end AE and the posterior end PEof hard palate HP. In the embodiment shown, tongue constraint 282extends in the posterior direction substantially the entire distancefrom the anterior end AE to the posterior end PE of hard palate HP, thusengaging both a medial region MR of the tongue T (roughly the middlethird) as well as regions of the tongue anterior and posterior to themedial region MR. Tongue constraint 282 creates a posterior opening Obounded superiorly by the hard palate, laterally by the teeth and bitestructure 284, and inferiorly by the posterior edge of plate 288. Thisposterior opening faces directly toward the soft palate SP and airway A,creating a vacuum flow path from the clear region CR directly to thesoft palate. This allows vacuum to be applied to at least the upperportion of the soft palate SP, from the superior end E1 where it joinsthe hard palate to a point closer the free inferior tip E2. Exertingvacuum force on the superior portion of the soft palate effectivelymaintains the entire soft palate structure in a position in which theairway is unobstructed.

In use, vacuum applied through vacuum tube 298 is directed to the tongueT through vacuum ports 296 and holds the tongue in engagement with theinferior surface of plate 288. Although some or all of vacuum ports 296may be blocked by the tongue, because the clear region maintained overoral device 280 is open posteriorly all the way to the soft palate, avacuum flow path is maintained from vacuum tube 298 directly to the softpalate. Thus the negative pressure within the clear region exerts aforce directly upon the soft palate through this vacuum flow path,maintaining the soft palate in an anterior position in which it does notobstruct the airway. Preferably, the suction force exerted on the softpalate through the clear region maintains the soft palate in sealingengagement with the tongue and/or with the soft palate landing pad 290,while the tongue is held in engagement with the inferior surface of thetongue restraint 282. This allows the airway to be substantially fluidlyisolated from clear space CR where the vacuum is applied such that thepressure gradient between the airway and the oral cavity increases, thusurging the soft palate, tongue and other posterior oral tissuesanteriorly out of the airway.

Still another embodiment of an oral device according to the invention isillustrated in FIGS. 15A-E. In this embodiment, oral device 310 isidentical to oral device 280 of FIGS. 14A-D except as described below.Oral device 310 has a bite structure 311 like that of the previousembodiment, and a tongue constraint 312 comprising a plate 313 with asoft palate landing pad 314. Unlike the straight posterior edge oflanding pad 290 in the previous embodiment, landing pad 314 has aposterior edge 315 with an arcuate shape that curves outwardly in theposterior and (optionally) inferior directions beyond the open end ofbite structure 311. With this shape landing pad 314 may be more suitablylocated to engage the soft palate in some patients. In addition, landingpad 314 optionally includes a plurality of ribs 318 extending laterallyacross landing pad 314. Ribs 318 stand in relief on the posteriorsurface 316 of landing pad 314 to enhance engagement with the softpalate tissue, as well as help to channel the vacuum flow laterally.Ribs 318 may comprise tubular, round, or partially-round strips affixedto landing pad 314, or ribs 318 may be integrally formed with landingpad 314. Ribs may also be provided along the superior surface of plate313 oriented either laterally like ribs 318 illustrated, in theanterior-posterior direction, or in other orientations.

A further difference from the embodiment of FIGS. 14A-D is the vacuumtube 320, which extends past apex A to a point near the posterior edge315 of oral device 310. In this way, vacuum tube 320 ensures thatnegative pressure is applied along the posterior edge of oral device310, a location closer to the soft palate. Vacuum tube 320 includes sideholes 322 and an open distal end 324 through which negative pressure maybe applied. Additionally, in this embodiment, tongue constraint 312 hasno vacuum ports extending through plate 313 as in the earlierembodiment.

Another unique aspect of oral device 310 is the placement of spacingelements 324 on the inferior surface 326 of bite structure 311. Spacingelements 324 are a soft pliable material, e.g. polymeric tubing or foam,having a thickness of about 2-12 mm. Each spacing elements 324 ispositioned at or near a posterior end 329 of bite structure 311 andextends anteriorly approximately 25-75% of the way around to the frontof bite structure 311. Alternatively, multiple spacing elements ofshorter length may be placed at intervals along each side of bitestructure 31. In this way spacing elements 325 sit between the patient'supper and lower teeth and hold open the lower jaw slightly. Such slightopening of the jaw during sleep has been shown to improve airway patencyin some circumstances.

A further unique aspect of oral device 310 is that a jaw positioning tab328 is disposed on the anterior closed end of bite structure 311 andextends downwardly therefrom sufficiently to engage the posteriorsurface of the lower front teeth when oral device 310 is positioned inthe oral cavity. Jaw positioning tab 328 is of sufficient stiffness andpositioned in a suitable location on bite structure 311 to maintain thepatient's lower jaw in a position slightly forward of a normal relaxedposition. Such forward positioning of the jaw has been found to improveairway patency in some circumstances.

It should be understood that ribs 318, spacing element 324, and jawpositioning tab 328 are optional features of oral device 310 and thatany or both of these features may be eliminated without departing fromthe scope of the invention or limiting its utility.

In other respects oral device 310 is similar to oral device 280 of FIGS.14A-D and operates in the same way. It will be understood that oraldevice 310 will usually include a lip seal like lip seal 306 of thepreviously described embodiment although in FIGS. 15A-D the lip seal isremoved for added clarity. It should be further understood that any orall of the features of oral device 310 may optionally be included inoral device 280 or in other embodiments described herein.

FIGS. 16A-C illustrate an oral device 330 identical to oral device 280of FIGS. 14A-D except an alternative configuration of vacuum tube 320 isshown. In this embodiment, vacuum tube 332 has a loop 334 extendingaround tongue constraint 313 near the outer edges thereof adjacent bitestructure 336 and along the posterior edge 338 of tongue constraint 313.Vacuum tube 320 has a plurality of side holes 337 distributed evenlyaround loop 334. A plurality of vacuum ports 339 are disposed in acentral region of tongue constraint 313 with loop 334 encircling most ifnot all of vacuum ports 339. In this way negative pressure isdistributed by vacuum tube 320 directly to the outer edges and posteriorregion of tongue constraint 313 to ensure adequate negative pressure isavailable in those regions. In addition, loop 334 more evenlydistributes negative pressure across a larger portion of the surface oftongue constraint 313.

FIGS. 17A-D illustrate an oral device 340 according to the inventionsimilar in many respects to oral device 280 of FIGS. 14A-D except, inplace of vacuum tube 320, oral device 340 has tongue constraint 341having a hollow interior chamber 342 enclosed between a superior wall344 and an inferior wall 346. A vacuum tube 348 is in fluidcommunication with chamber 342 and extends through inferior wall 346 andanteriorly through bite structure 350 where it may be connected to avacuum source. A plurality of inferior vacuum ports 352 extend throughinferior wall 346 in communication with chamber 342 and are positionedso as to apply suction to the tongue. A plurality of posterior vacuumports 354 extend through superior wall 344 in communication with chamber342 and are oriented to face in a posterior direction away from thetongue and toward the soft palate. Preferably, at least some ofposterior ports 354 are disposed in a plane P which is at an angle β ofat least about 45°, more preferably about 60°-180°, and most preferablyabout 90°-180° in the superior direction relative to the occlusal planeO which contains the inferior surface 349 of bite structure 343.Optionally, posterior vacuum ports 354 may be further distributed alongthe upper portion of superior wall 344 so as to face the hard palate. Inthis way, vacuum may be conveyed through vacuum tube 348 into chamber342, from which suction is applied to the tongue through inferior vacuumports 352 and to the soft palate through posterior vacuum ports 354.

In the embodiment of FIGS. 17A-C, tongue constraint 341 has an overallthickness (or height) greater than that of oral device 280 in order toprovide room for chamber 342; however, superior wall 344 will preferablybe configured so that a clear region is maintained above tongueconstraint 341 between the top surface of superior wall 344 and the hardpalate when oral device 340 is positioned in the oral cavity. As analternative, FIGS. 18A-C illustrate an oral device 340A substantiallyidentical to oral device 340 except in this embodiment, the superiorwall 344A extends upwardly to the hard palate such that the clear regionCR formed by tongue constraint 341A is enclosed within chamber 342A. Inthis embodiment, superior wall 344A is shaped so as to conform generallyto the shape of the hard palate and there will be little or no spacebetween superior wall 344A and the surface of the hard palate when oraldevice 340A is positioned in the oral cavity. Posterior ports 354A aswell as inferior ports 352A are thus in direct communication with theclear region CR within chamber 342A. As in the embodiment of FIGS.17A-D, posterior ports 354A face away from the tongue and toward thehard palate, preferably lying in a plane which forms an angle of atleast about 45°, more preferably about 60°-180°, and most preferablyabout 90°-180° in the superior direction relative to the occlusal plane.

In the embodiment of FIGS. 19A-D, oral device 360 is similar to oraldevice 340 of FIGS. 17A-D, except that tongue constraint 362 comprisestwo separate hollow chambers within it, including an anterior chamber364 and a posterior chamber 366, each enclosed by a superior wall 368and an inferior wall 370. Preferably, tongue constraint 362 is a moldedconstruction with anterior chamber 364 and posterior chamber 366integrally formed within it. A transverse wall 372 divides anteriorchamber 364 from posterior chamber 366. A plurality of inferior ports374 are disposed in inferior wall 370 in communication with anteriorchamber 364, and a plurality of posterior ports 376 are disposed insuperior wall 368 in communication with posterior chamber 366. As inother embodiments, inferior ports 374 are positioned so as to applysuction to the tongue, while posterior ports 376 are positioned so as toface away from the tongue and toward the soft palate in order to applysuction to the soft palate and not be blocked by the tongue when it isengaged by inferior wall 370. As described above in connection withFIGS. 17A-D, at least some of posterior ports 376 are disposed in aplane which is at an angle of at least about 45°, more preferably about60°-180°, and most preferably about 90°-180° in the superior directionrelative to the occlusal plane. An anterior supply conduit 380 extendsthrough tongue constraint 362 from anterior chamber 364 to the anteriorend of tongue constraint 362, while a posterior supply conduit 382extends from posterior chamber 366 to the anterior end of tongueconstraint 362. A first vacuum tube 384 connects to anterior supplyconduit 380 and a second vacuum tube 386 connects to posterior supplyconduit 382, each vacuum tube extending through bite structure 388 andbeing configured to connect to a vacuum source.

Oral device 360 is particularly advantageous in that the negativepressures within anterior chamber 364 and posterior chamber 366 can becontrolled independently of one another. As illustrated in FIG. 19E,vacuum tubes 384, 386 may be connected to separate pressure regulators385A, 385B, which are in turn fluidly connected to a single vacuum pump387. Pressure regulators 385 are adjustable using control knobs 389A,389B to set the level of negative pressure applied through each ofvacuum tubes 384, 386. In this way, the negative pressure in each ofanterior chamber 364 and posterior chamber 366 (not shown in FIG. 19E)can be independently controlled and optimized to keep the soft palateand tongue free of the airway. For example, different pressures could beapplied to different regions of the oral cavity (e.g. the tongue and thesoft palate) to achieve the desired displacement of different tissues.In addition, air under positive pressure can be delivered through eithervacuum tube 384 or vacuum tube 386 while air at a different pressure ornegative pressure is delivered through the other vacuum tube, forpurposes of removing saliva from the vacuum tubes, delivering positivepressure to the airway or other regions, or achieving other desiredeffects. In an alternative embodiment, vacuum tubes 384, 386 may beconnected to two separate pumps which are independently controllable toadjust the level of positive or negative pressure delivered, as shown inFIG. 23C, described below.

Turning to FIGS. 20A-C, in a further embodiment, oral device 390 isconstructed identically to oral device 280 of FIGS. 14A-D except thattongue constraint 392 includes an inferior pad 394 adhered to theinferior surface of tongue constraint 392, and a posterior pad 396adhered to a posterior surface of tongue constraint 392. Inferior pad394 and posterior pad 396 are composed of a soft, flexible and porousmaterial such as Dacron, cotton, or foam, and are adapted to reducefriction and abrasion of the tongue and/or soft palate tissues whichengage tongue constraint 392. Inferior pad 394 and posterior pad 394 aresufficiently porous to allow vacuum to be applied through them frominferior vacuum ports 398 or posterior vacuum ports 399. It should beappreciated that either inferior pad 394 or posterior pad 396 mayoptionally be used without the other, and that either or both inferiorpad 394 or posterior pad 396 could be used with any of the otherembodiments described above or below.

FIGS. 21A-B illustrate a further embodiment of an oral device accordingto the invention. In this embodiment, like other embodiments elsewheredescribed, oral device 400 comprises a tongue constraint 402 and a bitestructure 404. Tongue constraint 402 comprises a dome-shape plate 403with a plurality of inferior vacuum ports 408 extending through plate403 in a central region thereof. An anterior vacuum tube 406 is fixed tothe superior surface of plate 403 and has a plurality of side holes 405through which vacuum may be conveyed.

Different from previously describe embodiments, a landing pad 410 ispivotally coupled to tongue constraint 402 by a transverse pin 412, sothat landing pad 410 is rotationally movable relative to plate 403.Landing pad 410 has a hollow interior chamber 414 enclosed by aposterior wall 416 and an anterior wall 418. A plurality of posteriorports 420 are disposed in posterior wall 416 in communication withchamber 414. As in the embodiments of FIGS. 17-19, posterior ports 420are configured to face the soft palate and away from the tongue,preferably being disposed plane which is at an angle β of at least about45°, more preferably about 60°-180°, and most preferably about 90°-180°in the superior direction relative to the occlusal plane. Notably, theangle of posterior ports 420 relative to the occlusal plane may bevaried by pivoting landing pad 410 relative to plate 403.

A posterior vacuum tube 422 is connected to anterior wall 418 incommunication with chamber 414. Posterior vacuum tube 422 extendsanteriorly along the inferior side of plate 403, which optionally mayinclude eyelets 424 through which posterior vacuum tube is slidablypositioned to keep it close to plate 403. Posterior vacuum tube 422extends slidably through bite structure 404 and a clamp 426 fixed to theanterior side thereof. Clamp 426 has a cap 428 threaded onto a taperedreceptacle 430 each having a central passage through which posteriorvacuum tube extends. Tapered receptacle 430 may be axially split and/orsufficiently conformable that tapered receptacle 430 is urged radiallyinward to engage posterior vacuum tube 422 as cap 428 is rotationallytightened. Of course, various clamps suitable for clamping posteriorvacuum tube 422 are well known and may be used in place of the exemplaryclamp illustrated. By sliding posterior vacuum tube 422 anteriorly orposteriorly, landing pad 410 is pivoted relative to plate 403. It shouldbe understood that pull wires, rods, or other means could be usedinstead of posterior vacuum tube to pivot landing pad 403.

Advantageously, different negative pressures may be applied throughanterior vacuum tube 406 and posterior vacuum tube 422 so that thesuction applied to the soft palate through posterior ports 420 may becontrolled independently of the suction applied to the tongue throughinferior ports 408. For example, oral device 400 may be used with thesystem illustrated in FIG. 19E or the system illustrated in FIG. 23C.When vacuum has been applied through posterior ports 420 such the softpalate has become engaged against landing pad 410, posterior vacuum tube422 maybe tensioned to pivot landing pad 410 anteriorly, thereby helpingto draw the soft palate further away from the patient's airway. Oncelanding pad 410 is in the desired position, clamp 426 may be tightenedto lock the posterior vacuum tube 422 and landing pad 410 in place.

Referring now to FIGS. 22 and 22A-B, in a further embodiment an oraldevice 434 comprises a tongue constraint 436 movably coupled to a bitestructure 438. Tongue constraint 436 has a superior wall 440 and aninferior wall 442 enclosing a hollow chamber 444. A plurality ofinferior ports 446 extend through inferior wall 442 in communicationwith chamber 444. A plurality of posterior ports 448 are disposed in aposterior region of superior wall 440 in communication with chamber 444.Posterior ports face toward the soft palate and away from the tongue toremain unobstructed by the tongue when vacuum is applied therethrough,preferably lying in a plane which is at an angle of at least about 45°,more preferably about 60°-180°, and most preferably about 90°-180° inthe superior direction relative to the occlusal plane. A vacuum tube 450is connected to tongue constraint 436 in communication with chamber 444and extends slidably through a channel 452 in bite structure 438. Aclamp 454 is mounted to bite structure 438 and is adapted to lock vacuumtube 450 in position relative to bite structure 438. Clamp 454 may beconstructed like clamp 426 of FIGS. 21A-B or may have any other knownclamp design suited for its purpose.

Bite structure 438 is U-shaped with a closed anterior end 439, an openposterior end 441, and an inner wall 456 along its interior side. A pairof channels 458 are disposed in inner wall 456 on opposing sides of bitestructure 438 near its open end 441. A pair of pins 460 are attached toopposing lateral sides of tongue constraint 436 and extend laterallythrough channels 458. Pins 460 are slidable in channels 458 so thattongue constraint 436 is movably anteriorly and posteriorly relative tobite structure 438. In this way, vacuum may be applied through vacuumtube 450 and chamber 444 so as to apply suction through inferior ports446 to the tongue, and through posterior ports 448 to the soft palate.When these tissues have been engaged, tension may be exerted on vacuumtube 450 to move tongue constraint 436 anteriorly relative to bitestructure 438, thereby retracting the tongue and soft palate furtherforward and away from the airway. Once in the desired position, vacuumtube 450 may be clamped in place by tightening clamp 454 so as to holdtongue restraint 436 in position relative to bite structure 438.

FIGS. 23A-B illustrate another embodiment of an oral device according tothe invention. In this embodiment, oral device 470 is identical to oraldevice 280 of FIGS. 14A-D except that oral device 470 is adapted todeliver air under positive pressure into the patient's airway while thetongue is constrained and negative pressure is applied to the softpalate and tongue. Oral device 470 includes at least one, preferably two(as shown), delivery conduits 472 fixed to the upper surface of tongueconstraint 474. Alternatively delivery conduits 472 may be fixed to bitestructure 476, e.g. to its inner wall 478 or to its inferior surface480. In the latter case delivery conduits 472 may serve the additionalpurpose of acting as a spacer between the patient's upper and lowerteeth to keep them slightly apart when the oral device is in place. As afurther alternative, all or part of delivery conduits 472 may be formedby an interior lumen (not shown) formed integrally within tongueconstraint 474 or bite structure 476. Delivery conduits 472 haveposterior portions 482 extending from the posterior edge 484 of tongueconstraint 474 with free posterior ends 486 adapted to extend into thepatient's airway. Delivery conduits 472 connect to a delivery tube 473which extends through bite structure 476 and is adapted to connect to afluid supply tube (not shown) outside the patient's oral cavity, whichin turn may be connected to pump (not shown) for delivering air or othergasses under positive pressure. Alternatively, delivery tube 473 may beopen to room air so that the airway is in communication with air outsidethe oral cavity in order to allow mouth breathing while the device is inplace and while the oral cavity seal is maintained.

As in the case of oral device 280, with oral device 470 in place in thepatient's oral cavity, tongue constraint 474 maintains at least aportion of the tongue in a position spaced apart from the patient's hardpalate so as to maintain a clear region superior to tongue constraint474. Negative pressure may be applied through vacuum lumen 488 to exertvacuum force on the soft palate and tongue, thereby causing the softpalate and tongue to be maintained in sealing engagement with oneanother anterior to the patient's airway, isolating the airway from theremainder of the oral cavity. The soft palate, tongue, and oral devicemay alternatively seal to each other in any combination in order tosubstantially fluidly isolate the airway. In this embodiment, deliveryconduits 472 are adapted to extend into the airway between the softpalate and tongue while still allowing these tissues to seal againsteach other and around the periphery of delivery conduits 472. Air orother suitable gasses may be delivered to the airway under positivepressure through delivery conduits 472 thereby enhancing the pressuregradient between the airway and the oral cavity, helping to urge thesoft palate and tongue anteriorly out of the airway and preferably insealing engagement with one another. Positive pressure delivered to theairway may also apply forces to other tissues in a manner that improvesairway patency.

A dual-pump system for use with oral device 470 is illustrated in FIG.23C. System 471 comprises a first pump 473 controlled via a control knob475A and a second pump 477 controlled via a second control know 475B. Afirst readout 479A displays the pressure level being applied by firstpump 473, while a second readout 479B displays the pressure level beingapplied by second pump 477. Delivery tube 473 is connected to first pump473 while vacuum tube 488 is connected to second pump 477. In this way,first pump 473 may deliver air under an adjustable level of positivepressure through delivery conduits 472, while second pump 477 may beadjusted to apply a desired level of negative pressure through vacuumlumen 488. Optionally, pressure lumens or sensors may be provided onoral device 470 to monitor negative pressure in the oral cavity and/orpositive pressure in the airway. These may be coupled to first andsecond pumps 473, 477 which may be automatically controlled to adjustpump speed or pressure to maintain desired pressure levels or a desiredpressure gradient between the airway and the oral cavity.

In a further embodiment of the invention, illustrated in FIGS. 24A-C, anoral device 580 is substantially identical to oral device 280 of FIGS.14A-D, except in this embodiment, oral device 580 comprises a tongueconstraint 581 having a plate 582 for engaging the patient's tongue anda landing pad 584 which extends in a generally superior direction from aposterior edge 586 of plate 582. As shown in FIG. 24C, landing pad 584has a posterior surface 588 at least a portion of which lies in a planeP which is at an angle α of at least about 30°, more preferably about45-135°, and most preferably about 60-100° relative to the occlusalplane H containing the inferior surface 589 of bite structure 590. Inthis way, posterior surface 588 is configured to receive and engage thesoft palate as it is drawn forward by vacuum pressure applied throughvacuum tube 592. Posterior surface 588 may have a curvature either orboth laterally right-left and superiorly-inferiorly so as to present aconcave surface into which the soft palate is drawn. The superior edge595 of landing pad 584 preferably has an arched shape corresponding tothe shape of the hard palate, and may be configured to engage the hardpalate and even to seal therewith, or alternatively may be spaced apartfrom the hard palate. In addition, posterior edge 586 of plate 582,which forms the inferior edge of landing pad 584, may be disposed invarious positions relative to the occlusal plane H, including bothsuperior and inferior to plane H. In a particular embodiment, posterioredge 586 is disposed a distance d of about 2-7 mm, more preferably about3-6 mm, inferior to plane H.

A plurality of posterior ports 596 are disposed in landing pad 584 andextend through its thickness so that, with oral device 580 in place inthe patient's oral cavity, posterior ports 596, lying in plane P, facein a posterior direction directly toward the soft palate. In this way,the clear region created superior to plate P and below the hard palatecommunicates directly with the soft palate through posterior ports 596so that vacuum applied through vacuum tube 592 is applied directly tothe soft palate via posterior ports 596. Moreover, the verticalorientation of landing pad 584 and posterior ports 596 therein allowsvacuum to be applied to the entire soft palate, from its free inferiortip to its posterior end where it attaches to the hard palate, enhancingthe effectiveness of displacing the soft palate from the patient'sairway. Because the patient's tongue is constrained under the inferiorsurface of plate 582, the tongue cannot be pulled by the vacuum forcesto obstruct posterior ports 596. Inferior ports (not shown) mayoptionally be provided in plate 582 through which vacuum may be exertedupon the superior surface of the tongue, similar to the embodiment ofFIGS. 14A-D.

FIG. 25 illustrates a further embodiment of a system 489 according tothe invention including an oral device 490, a vacuum pump 492, a salivareservoir 494, and a pressure sensor 496. Oral device 490 may beconfigured like any of the oral devices described above, such as oraldevice 280 of FIGS. 14A-D. However, oral device 490 further includes apressure conduit 498 extending through bite structure 500 to thesuperior side of tongue constraint 502 where pressure conduit 498 has adistal opening 504. It should be understood that pressure conduit 498may alternatively comprise an inner lumen formed integrally withintongue constraint 502 or bite structure 500, and distal opening 504could be positioned in any of various positions relative to bitestructure 500 as may be desired to measure pressure within the oralcavity. A vacuum lumen 506 extends from the superior surface of tongueconstraint 502 through bite structure 500 and both vacuum lumen 506 andpressure conduit 498 extend through lip seal 508. Vacuum lumen 506 isconnected to a vacuum tube 510 which connects in an airtight manner toan input fitting 512 on saliva reservoir 494. Vacuum tube 510 has a venthole 511 anterior to lip seal 508 so as to be outside the patient's oralcavity but positioned as close to oral device 490 as practicable whileminimizing risk of obstruction by the patient's lips or other tissues.Alternatively vent hole 511 may be disposed in vacuum lumen 506 anteriorto bite structure 500 or on the superior side of tongue constraint 502so as to be located within the patient's oral cavity. When negativepressure is applied through vacuum lumen 506 within the patient's oralcavity, saliva or other liquids which collect may be aspirated throughvacuum lumen 506 and vacuum tube 510. While removing excess liquids fromthe oral cavity is desirable, the weight of the liquid within vacuumtube 510 may create a pressure offset in vacuum tube 510 which wouldthen affect the negative pressure applied within the oral cavity. System489 alleviates this problem by providing vent hole 511 in vacuum tube510, allowing any aspirated liquids to flow to saliva reservoir 494 morequickly.

Saliva reservoir 494 has an output fitting 516 which creates an airtightconnection with an output tube 518 fluidly connected to vacuum pump 492.Saliva reservoir 494 has a liquid collector 517 which has an airtightinterior and has sufficient depth to maintain liquid-free space 519between the level of liquid L collected therein and the height of inputfitting 512 and output fitting 516; in this way, negative pressureapplied by vacuum pump 492 is exerted through the liquid-free space 519within collector 517 and thus through vacuum tube 510. In an exemplaryembodiment, collector 517 has an interior volume of about 20-1000 ml andwill have an overall depth which exceeds the maximum liquid levelexpected to be collected in collector 517 over a typical 8 hour sleepcycle so that the liquid level does not rise to the level of fittings512, 516. Saliva reservoir 494 may also contain a substance whichabsorbs, deodorizes, and/or sanitizes the saliva. In addition, salivareservoir 494 may have a heating element to heat the saliva in order toevaporate or boil away excess volume.

Pressure lumen 498 is connected to a pressure tube 514 which connects topressure sensor 496. Pressure sensor 496 is adapted to produce anelectronic signal in response to the pressure sensed in pressure tube514, and is electronically connected to vacuum pump 492 by a wire 520.Vacuum pump 492 has an electronic controller (not shown) responsive tosignals received from pressure sensor 496, whereby the negative pressureapplied by vacuum pump 492 may be regulated in a manner to maintain adesired level of negative pressure within the patient's oral cavity withoral device 490 in place. In this way, if the pressure within the oralcavity changes as a result of a loss of seal either in the lips orbetween the tongue and the soft palate, an excess of saliva aspiratedthrough vacuum lumen 506, or other factors, pressure sensor 496 sensessuch change and vacuum pump 492 is automatically regulated to maintainthe negative pressure at the desired level.

A further embodiment of a system constructed in accordance with theinvention is illustrated in FIG. 26. System 530 comprises an oral device532 and a control unit 534. Oral device 532 may be configured asdescribed in connection with in any of the other embodiments describedherein, for example, oral device 280 of FIGS. 14A-D. However, in thisembodiment, oral device 532 further includes one or more sensors 536,538 mounted thereon. Sensors 536, 538 may comprise any of a variety ofsensors for detecting various physiological conditions within the oralcavity, including oximetry sensors for detecting oxygen levels in theoral cavity or in the blood within oral tissues, impedance sensors fordetecting contact with the tongue or other tissues, accelerometers fordetecting head position or orientation, thermistors for detectingtemperature, microphones or piezoelectric sensors for detecting soundsor vibrations such as snoring or teeth grinding, or heartbeat, moisturesensors for detecting liquid or hydration of oral tissues, flow sensorsfor detecting air flow in the oral cavity or airway, or pressure sensorsfor detecting pressure within the oral cavity. The positions illustratedfor sensors 536, 538 are merely exemplary and will be selected accordingto the type of sensor and the conditions being detected. For example, animpedence sensor for detecting contact with the patient's tongue couldbe mounted on the inferior side of tongue constraint 540 so as todirectly contact the patient's tongue. A thermistor for detecting nasalair flow could be mounted on the superior side of vacuum lumen 542anterior to lip seal 544 so as to be positioned directly under thepatient's nostrils, thereby detecting the temperature (and presence) ofexhaled air from the nostrils. Piezoelectric sensors for detecting teethgrinding could be mounted on bite structure 546 so as to be contactingor proximate to the teeth.

In a particular embodiment, sensor 536 comprises a pressure transducerfor detecting pressure within the patient's oral cavity while sensor 538comprises an oximetry sensor for detecting oxygen levels in the oralcavity or in surrounding tissues or blood therein. Detecting pressurewithin the oral cavity may be useful to detect whether a seal is beingmaintained between the tongue and soft palate such that the airway isisolated from the that portion of the oral cavity in which negativepressure is being applied via oral device 532. In addition, pressuredata may be used to provide feedback to the vacuum pump applying suchnegative pressure in order to automatically regulate and maintain thelevel of negative pressure being applied, as described above inconnection with FIG. 25. Oximetry sensor 538 is preferably a pulseoxymetry sensor for detecting oxygen saturation levels in the oralcavity or in the tissues surrounding the oral cavity such as the tongue,cheeks, gums, or hard or soft palates. Oxygen levels in the blood or inthe oral cavity may be detected to determine whether the patient isreceiving adequate oxygen during sleep, i.e., whether the patient'sairway is unobstructed.

Vacuum lumen 542 extends through lip seal 544 and connects, preferablythrough a detachable fitting (not shown), to a vacuum tube 548 having avent hole 550 as in the embodiment of FIG. 25. A pressure lead 552 iscoupled to pressure transducer 536 and extends through lip seal 544 tocontrol unit 530. An oximeter lead 554 is coupled to oximetry sensor 538and extends through lip seal 544 to control unit 530. Preferablypressure lead 552 and oximeter lead 554 have detachable couplings (notshown) anterior to lip seal 544 to allow detachment of oral device 532from control unit 530.

Control unit 534 includes a vacuum pump 556 the output (suction) orificeof which is fluidly coupled to a saliva reservoir 558 constructed andoperated as described above in connection with FIG. 25. Preferably,control unit 534 has an opening 559 through which saliva reservoir 558may be removed and emptied. Vacuum tube 548 connects to control unit 530in which it is fluidly connected to saliva reservoir 558. Vacuum pump556 is connected to a power supply 563 which connects to an AC powersource via cord 565. The speed and/or pressure of vacuum pump 556 may bemanually controlled by a switch 561 electrically coupled to vacuum pump556 or to power supply 563.

Pressure lead 552 is coupled to a pressure sensor interface 560 andoximeter lead 554 is coupled to an oximeter sensor interface 562.Pressure sensor interface 560 and oximeter sensor interface 562 are eachconnected to a computerized controller 564. Controller 564 is adapted toreceive signals generated by pressure signal generator 560 and oximetersignal generator 562, process those signals, and electronically controlvacuum pump 556 to regulate the negative pressure being appliedtherewith and thereby optimize device performance and the physiologiccondition of the patient. Preferably, so long as oxygen levels detectedby oximetry sensor 538 are satisfactory, controller 564 will regulatevacuum pump 556 to maintain constant pressure as measured by pressuretransducer 536. However, if the detected oxygen reaches an unacceptablylow level, controller 564 may be adapted to automatically boost pumpspeed to increase the level of negative pressure being applied via oraldevice 532. Computerized controller 564 will include a centralprocessing unit (CPU) and will be connected to a memory device 567 whichmay comprise a fixed read only memory device and/or random access memorydevice, and optionally a removable memory device such as a flash drive,optical disk, or other removable data storage medium. Data collectedfrom sensors 536, 538, as well as system performance data and otherinformation may be saved in memory device 567 and recalled by controller564.

Additional optional components of control unit 534 include an electronicdisplay 566, audio speaker 568, a docking station 570 suitable foriPhone, iPod or other portable device, a wireless transceiver (e.g.Bluetooth) or modem 572, a data connector 569 for connection to datacables from other computerized devices, and saliva level sensor (notshown) in saliva reservoir 558, each being electrically coupled tocontroller 564. Display 566 displays information output to the user fromcontroller 564 including information regarding pressure readings,oximetry readings, data from any other sensors on oral device 532,current pump speed or outlet pressure, sensor readings over a desiredtime period, messages or reminders to the user, indications that vacuumtube 548 is clogged or saliva reservoir 558 is full, and other pertinentinformation. Control unit 534 preferably includes a user input device toallow the user to input commands and other information. Display 566 maybe a touchscreen display or a separate keyboard (not shown) may becoupled to controller 564. Speaker 568 may similarly provide informationto the user including alerts or alarms, e.g. that the pressures are notbeing maintained or oxygen levels are too low, as well as playing musicor other sounds to help the patient sleep or to wake at a desired time.Logged data, saved in memory device 567, may be output to display 566,to a portable device via docking station 570, or to another device viadata connector 569 or wireless transmitter/modem 572. Control unit 534is preferably programmable such that the user may select the amount ofnegative pressure applied, the length of time it is to be applied,alarms to triggered, data to be recorded and logged, and otherparameters, according to conditions detected in the oral cavity bysensors 536, 538, time of day, or other factors. Control unit 534 mayalso employ software to allow it to calculate and automatically selectsuitable operating parameters based on personal health information inputby the user.

In other alternative embodiments, the oral device of the invention mayinclude features to treat other conditions during sleep along with sleepapnea. For example, the oral device of the invention may include a bitestructure like bite structure 284 of FIGS. 14A-D which is adapted toapply forces to the patient's teeth to straighten the teeth graduallyover time, similar to orthodontic appliances. The bite structure may becustom molded to the patient's teeth and periodically replaced withstructures of gradually altered shapes to gently move the teeth into adesired position. Optionally, the bite structure may be detachable fromthe tongue constraint and vacuum lumen(s) to allow for easy replacementof various bite structures. In another alternative embodiment, the bitestructure may be adapted to reduce bruxisim, or teeth grinding, whilethe oral device of the invention is being used to maintain airwaypatency.

As a further optional feature, the bite structure of the oral device maybe adapted to retain bleaching agents or other cosmetic or therapeuticmaterials in contact with the patient's teeth while the oral device isbeing worn. The bite structure may again have the U-shaped configurationof bite structure 284 of FIGS. 14A-D, and may be custom molded to fitclosely around the patient's top teeth. A separate bleaching tray ofconventional design could be used for the bottom teeth, or optionallythe bite structure could be configured to fit around both the top andbottom teeth so that the agents could be applied to both with the samedevice. The bite structure will be continuous and free of holes or voidsthroughout the area where the agent is to be applied so that the agentdoes not leak out while the device is being worn.

The invention may further be utilized in conjunction with otherapparatus for the treatment of sleep apnea. For example, oral devicesand systems described herein may be used in conjunction with aconventional CPAP apparatus for delivering air under positive pressureto the nasal airway. In this way, with the device of the inventionapplying negative pressure within the oral cavity, and the CPAPapparatus increasing pressure in the airway, the pressure gradientbetween the airway and the oral cavity is further increased, thus urgingthe soft palate and tongue anteriorly out of the airway.

In addition the devices and systems of the invention may be used inconjunction with one-way nasal valve devices, such as those describedin, for example, U.S. patent application Ser. No. 11/941,915, filed Nov.16, 2007, and Ser. No. 11/811,339, filed Jun. 7, 2007, which are herebyincorporated herein by reference. Again, by increasing airway pressureusing such nasal valve devices while decreasing pressure in the oralcavity using the present invention, the pressure gradient from airway tooral cavity is increased, thus urging the soft palate and tongue out ofthe airway.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications, substitutions,and equivalents may be used. Therefore, the above description should notbe taken as limiting the scope of the invention, which is defined by theappended claims.

1. A method for improving airway patency in a patient having an oralcavity, a hard palate, a soft palate, a tongue, lips, and an airway,said method comprising: placing an oral device in the oral cavity, theoral device having a tongue constraint to engage a medial surface of thetongue, the tongue constraint constraining the medial surface in aposition spaced-apart from the hard palate, whereby a continuous vacuumflow path extends from the lips to the soft palate; and applying avacuum through the vacuum flow path to the soft palate, wherein the softpalate forms a seal against one or both of the tongue and the oraldevice such that the airway is substantially fluidly isolated from thevacuum flow path.
 2. A method as in claim 1 wherein the tongueconstraint engages the medial surface at a point at least about ⅓ of thedistance from an anterior tip of the tongue to a posterior end of thetongue.
 3. A method as in claim 1 wherein the tongue constraintcomprises a plate having a width at least about ½ the width of thetongue.
 4. A method as in claim 1 wherein the tongue constraint engagesthe medial surface at a point posterior to the midpoint between ananterior end of the hard palate and a posterior end of the hard palate.5. A method as in claim 1 wherein the vacuum flow path comprises a clearregion formed between the tongue and the hard palate.
 6. A method as inclaim 1 wherein the vacuum flow path comprises a vacuum lumen integralwith or coupled to the oral device.
 7. A method as in claim 1, furthercomprising delivering positive pressure to the airway posterior to theseal.
 8. A method as in claim 7 wherein the positive pressure isdelivered through the oral cavity.
 9. A method as in claim 7 wherein thepositive pressure is delivered through the nasal airway.
 10. A method asin claim 1 further comprising positioning a pressure monitor in the oralcavity to monitor for leaks.
 11. A method as in claim 2 wherein theclear region is in fluid communication with the soft palate through anopening facing away from the tongue.
 12. A method as in claim 1 furthercomprising applying a vacuum to a superior surface of the tongue.
 13. Amethod as in claim 12 wherein the vacuum is applied to the superiorsurface of the tongue through an inferior port in the oral device.
 14. Amethod as in claim 1 further comprising applying a vacuum to a lateralsurface of the tongue.
 15. A method as in claim 1 wherein the vacuum isapplied through a first port oriented away from the tongue such that thefirst port remains unblocked by the tongue.
 16. A method as in claim 15wherein the vacuum is further applied through a second port orientedtoward the tongue.
 17. A method as in claim 1, wherein the vacuum has apressure in the range from −5 cm H₂O to −150 cm H₂O.
 18. A method as inclaim 1, further comprising sealing the patient's lips to inhibit airentering the oral cavity while the vacuum is being applied.
 19. A methodas in claim 18, wherein sealing the lips comprises positioning a sealingstructure between the lips and the teeth.
 20. A method as in claim 1further comprising repositioning the patient's jaw from an undeflectedposition to a deflected position, and maintaining the jaw in thedeflected position while the vacuum is applied.
 21. A method as in claim1 further comprising collecting saliva aspirated from the oral cavity bythe vacuum.
 22. A method for improving airway patency in a patienthaving an oral cavity, a hard palate, a soft palate, a tongue, and anairway, said method comprising: constraining a medial surface of thepatient's tongue to maintain a clear region between the medial surfaceand the hard palate, the medial surface being at least in part posteriorto the midpoint between an anterior end of the hard palate and aposterior end of the hard palate, the clear region being in fluidcommunication with the soft palate through a posterior openingconfigured to apply vacuum toward an anterior surface of the softpalate; and applying a negative pressure within the clear region to holdthe soft palate in a position in which the airway is at least partiallyopen, wherein the posterior opening remains unobstructed by the tonguewhen the negative pressure is applied and the soft palate and tongueform a seal whereby the patient's airway is substantially fluidlyisolated from the clear region.
 23. A method as in claim 22 wherein themedial surface is constrained at a point at least about ⅓ of thedistance from an anterior tip of the tongue to a posterior end of thetongue.
 24. A method as in claim 22 wherein the medial surface isconstrained at a point at least about ½ of the distance from theanterior end of the hard palate to the posterior end of the hard palate.25. A method as in claim 22 wherein the medial surface is constrained bya tongue constraint positioned in the patient's oral cavity.
 26. Amethod as in claim 25 wherein the tongue has a width and the tongueconstraint engages the tongue across at least a majority of the width.27. A method as in claim 26 wherein the tongue constraint comprises aplate.
 28. A method as in claim 27 wherein the plate spans across aspace between the patient's left and right molars.
 29. A method as inclaim 25 wherein the clear region is in communication with at least oneinferior port in the tongue constraint facing toward the tongue.
 30. Amethod as in claim 29 wherein when negative pressure is applied at leastone inferior port is blocked by the tongue while the posterior openingremains unobstructed by the tongue.
 31. A method as in claim 25 whereinthe soft palate engages one or both of the tongue and the tongueconstraint to create the seal.
 32. A method as in claim 22 wherein fluidwithin the clear region is in direct contact with an inferior surface ofthe hard palate.
 33. A method as in claim 25 wherein the negativepressure is applied through at least one vacuum lumen coupled to orintegral with the tongue constraint.
 34. A method as in claim 25,wherein the negative pressure is applied through at least one vacuumlumen positioned in the oral cavity separately from the tongueconstraint.
 35. A method as in claim 25, further comprising positioningan anchor structure in the oral cavity, the tongue constraint beingcoupled to or integral with the anchor structure.
 36. A method as inclaim 35 wherein the tongue constraint has opposing lateral edgesextending from an anterior end to a posterior end thereof, at least aposterior portion of the lateral edges being fixed to the anchorstructure.
 37. A method as in claim 35 wherein positioning the anchorstructure comprises holding a bite structure between the teeth.
 38. Amethod as in claim 37, wherein the bite structure comprises at least onebite surface which is held between the teeth.
 39. A method as in claim37, wherein the bite structure comprises a tooth-receiving channel whichreceives the teeth.
 40. A method as in claim 35, wherein positioning theanchor structure comprises engaging a hard palate engagement surfaceagainst the hard palate to hold the anchor in position.
 41. A method asin claim 22 further comprising placing a lip seal along the patient'slips to help seal the oral cavity when the negative pressure is applied.42. A method as in claim 25, wherein the negative pressure is appliedthrough a plenum network coupled to or integral with the tongueconstraint.
 43. A method as in claim 42, wherein the plenum networkextends within at least a portion of the tongue constraint.
 44. A methodas in claim 42, wherein the plenum network extends within a bitestructure coupled to or integral with the tongue constraint.
 45. Amethod as in claim 42, wherein the plenum network extends down at leastone lateral side of the tongue.
 46. A method as in claim 22 furthercomprising detecting a leak in the sealed region of the oral cavity witha detector positioned in the oral cavity.
 47. A method as in claim 22further comprising receiving an indication of airway patency from asensor positioned in the oral cavity.
 48. A method as in claim 22further comprising aspirating liquid which accumulates in the oralcavity.
 49. A method as in claim 48, further comprising maintaining asubstantially constant negative pressure while the liquid is aspirated.50. A method as in claim 22 further comprising delivering positivepressure to the airway while the negative pressure is applied.
 51. Amethod as in claim 50 wherein the positive pressure is delivered throughthe oral cavity.
 52. A method as in claim 50 wherein the positivepressure is delivered through the nasal airway.
 53. A method as in claim22 further comprising repositioning the patient's jaw from anundeflected position to a deflected position, and maintaining the jaw inthe deflected position while the negative pressure is applied.
 54. Amethod as in claim 22 wherein the posterior opening lies in a firstplane which is disposed at an angle of at least about 45 degreesrelative to an occlusal plane defined by a plane of contact between thepatient's upper and lower teeth.
 55. A method as in claim 54 wherein thefirst plane is about 45-180 degrees relative to the occlusal plane. 56.A method as in claim 25 wherein the posterior opening is bounded on aninferior side by the tongue constraint and on a superior side by thepatient's hard or soft palate.
 57. A method as in claim 22 wherein thesoft palate has an upper portion with an upper end joined to the hardpalate and a lower portion with a lower end which is unattached, andwherein the posterior opening is configured to apply negative pressuredirectly to the upper portion when the airway is open.
 58. Apparatus forimproving airway patency comprising: an oral device positionable in apatient's oral cavity and having a tongue constraint to constrain amedial surface of the patient's tongue in a position spaced-apart fromthe hard palate, the oral device providing a continuous vacuum flow pathfrom the patient's lips to the patient's soft palate, the oral devicebeing configured to maintain a seal between the soft palate and one orboth of the tongue and the oral device when vacuum is applied throughthe vacuum flow path such that the airway is substantially fluidlyisolated from the vacuum flow path.
 59. Apparatus as in claim 58 whereinthe tongue constraint is configured to engage the medial surface at apoint at least about ⅓ of the distance from an anterior tip of thetongue to a posterior end of the tongue.
 60. Apparatus as in claim 58wherein the tongue has a width and the tongue constraint is configuredto engage the tongue across at least a majority of the width. 61.Apparatus as in claim 60 wherein the tongue constraint comprises aplate.
 62. Apparatus as in claim 58 wherein the tongue constraint isconfigured to engage the medial surface at a point posterior to themidpoint between an anterior end of the hard palate and a posterior endof the hard palate.
 63. Apparatus as in claim 58 wherein the vacuum flowpath comprises a clear region formed between the tongue and the hardpalate.
 64. Apparatus as in claim 58 wherein the vacuum flow pathcomprises a vacuum lumen integral with or coupled to the oral device.65. Apparatus as in claim 58, further comprising a delivery lumencoupled to the oral device adapted to deliver positive pressure to theairway.
 66. Apparatus as in claim 58 further comprising a pressuremonitor coupled to the oral device.
 67. Apparatus as in claim 58 furthercomprising an oximetry sensor coupled to the oral device.
 68. Apparatusas in claim 63 wherein the clear region is in fluid communication withthe soft palate through an opening configured to apply vacuum to ananterior surface of the soft palate.
 69. Apparatus as in claim 68wherein the oral device comprises an inferior port in communication withthe vacuum flow path and configured to apply vacuum to a superiorsurface of the tongue.
 70. Apparatus as in claim 58 wherein the oraldevice further comprises a lateral port configured to apply vacuum to alateral surface of the tongue.
 71. Apparatus as in claim 58 wherein theoral device comprises a posterior port in communication with the vacuumflow path and facing away from the tongue so as remain unblocked by thetongue when vacuum is applied.
 72. Apparatus as in claim 71 wherein theoral device further comprises an inferior port oriented toward thetongue.
 73. Apparatus as in claim 72 wherein the inferior port is incommunication with the vacuum flow path.
 74. Apparatus as in claim 72wherein the inferior port is in communication with a vacuum lumenfluidly separate from the vacuum flow path.
 75. Apparatus of claim 58,further comprising a lip seal for sealing the patient's lips to inhibitleaks into the oral cavity.
 76. Apparatus as in claim 72, wherein thelip seal comprises a sealing structure positionable between the lips andthe teeth.
 77. Apparatus as in claim 58 further comprising a jawengagement structure coupled to the oral device adapted to maintain thepatient's jaw in a deflected position selected to help keep the airwayopen.
 78. Apparatus of claim 77 wherein the jaw engagement structurecomprises a tab on the oral device adapted to engage the patient's lowerteeth to maintain the lower jaw in an anterior position.
 79. Apparatusof claim 77 wherein the jaw engagement structure comprises a spacerdisposed on the oral device and positionable between the patient's upperand lower teeth to maintain the jaw in an open position.
 80. Apparatusas in claim 64 wherein the oral device further comprises an anchorstructure adapted to maintain the position of the oral device within theoral cavity.
 81. Apparatus as in claim 80 wherein the tongue constrainthas opposing lateral edges extending from an anterior end to a posteriorend thereof, at least a posterior portion of the lateral edges beingfixed to the anchor structure.
 82. Apparatus as in claim 80 wherein theanchor structure comprises a bite structure adapted to be held by thepatient's teeth.
 83. Apparatus as in claim 58 further comprising avacuum source connectable to the oral device in fluid communication withthe vacuum flow path.
 84. An oral device for improving patency of apatient's airway, comprising: a tongue constraint positionable in anoral cavity and adapted to engage a medial surface of a tongue andconstrain the medial surface in a position spaced-apart from a hardpalate so as to create a clear region therebetween, the medial surfacebeing at least in part posterior to the midpoint between an anterior endof the hard palate and a posterior end of the hard palate, the clearregion being in communication with a soft palate through a posterioropening configured to apply vacuum toward an anterior surface of thesoft palate; and means for conveying a vacuum to the clear region whilethe tongue constraint engages the tongue such that the soft palate isheld in a position in which the airway is at least partially open andthe posterior opening remains unobstructed by the tongue, wherein thesoft palate and tongue form a seal whereby the patient's airway issubstantially fluidly isolated from the clear region.
 85. An oral deviceas in claim 84 wherein the tongue constraint is configured to engage themedial surface at a point at least about ⅓ of the distance from ananterior tip of the tongue to a posterior end of the tongue.
 86. An oraldevice as in claim 84 wherein the tongue has a width and the tongueconstraint is configured to engage the tongue across at least a majorityof the width.
 87. An oral device as in claim 86 wherein the tongueconstraint comprises a plate.
 88. An oral device as in claim 87 whereinthe plate is configured to span across a space between the patient'sleft and right molars.
 89. An oral device as in claim 84 wherein theclear region is further in communication with at least one inferior portin the tongue constraint facing toward the tongue.
 90. An oral device asin claim 84 wherein the tongue constraint is adapted to maintain thesoft palate in engagement with one or both of the tongue and the tongueconstraint to create the seal when vacuum is conveyed to the clearregion.
 91. An oral device as in claim 84 wherein the tongue constraintis configured such that fluid within the clear region directly contactsan inferior surface of the hard palate.
 92. An oral device as in claim84 wherein the means for conveying the vacuum comprises at least onevacuum lumen coupled to or integral with the tongue constraint.
 93. Anoral device as in claim 84 further comprising an anchor structurecoupled to or integral with the tongue constraint.
 94. An oral device asin claim 93 wherein the tongue constraint has opposing lateral edgesextending from an anterior end to a posterior end thereof, at least aposterior portion of the lateral edges being fixed to the anchorstructure.
 95. An oral device as in claim 93 wherein the anchorstructure comprises a bite structure positionable between the upper andlower teeth.
 96. An oral device as in claim 95, wherein the bitestructure comprises a tooth-receiving channel which receives the teeth.97. An oral device as in claim 95, wherein the anchor structurecomprises a hard palate engagement surface positionable against the hardpalate to hold the tongue constraint in position.
 98. An oral device asin claim 84 further comprising a lip seal positionable along thepatient's lips to help seal the oral cavity when vacuum is applied. 99.An oral device as in claim 84, wherein the means for conveying a vacuumcomprises a plenum network coupled to or integral with the tongueconstraint.
 100. An oral device as in claim 99, wherein the plenumnetwork extends within at least a portion of the tongue constraint. 101.An oral device as in claim 99, wherein the plenum network extends withina bite structure coupled to or integral with the tongue constraint. 102.An oral device as in claim 99, wherein the plenum network extends downat least one lateral side of the tongue.
 103. An oral device as in claim84 further comprising a pressure sensor coupled to the tongue constraintfor monitoring pressure in the oral cavity.
 104. An oral device as inclaim 84 further comprising an oximetry sensor coupled to the tongueconstraint for monitoring the patient's oxygen level.
 105. An oraldevice as in claim 84 further comprising a pressure lumen coupled to thetongue constraint adapted to deliver positive pressure to the airway.106. An oral device as in claim 84 further comprising a jaw engagementstructure coupled to the tongue constraint and adapted to maintain thepatient's jaw in a deflected position selected to help keep the airwayopen.
 107. An oral device as in claim 106 wherein the jaw engagementstructure comprises a tab on the oral device adapted to engage thepatient's lower teeth to maintain the lower jaw in an anterior position.108. An oral device as in claim 106 wherein the jaw engagement structurecomprises a spacer disposed on the oral device and positionable betweenthe patient's upper and lower teeth to maintain the jaw in an openposition.
 109. An oral device as in claim 84 further comprising a softpad on a posterior surface of the tongue constraint configured to engagethe soft palate.
 110. An oral device as in claim 84 further comprising asoft pad on an inferior surface of the tongue constraint configured toengage the tongue.
 111. An oral device as in claim 95 wherein the tongueconstraint is movably coupled to the anchor structure to allow thetongue constraint to move anteriorly within the jaw cavity to repositionthe tongue therein.
 112. An oral device as in claim 84 furthercomprising a soft palate landing surface coupled to or integral with thetongue constraint, the soft palate landing surface having a posteriorsurface adapted to engage the soft palate when the soft palate is in theposition wherein the airway is at least partially open.
 113. An oraldevice as in claim 112 wherein the soft palate landing surface ismovably coupled to the tongue constraint.
 114. An oral device as inclaim 112 wherein the soft palate landing surface has a posterior portthereon adapted to convey a vacuum toward the soft palate.
 115. An oraldevice as in claim 112 wherein the posterior surface is disposed at anangle of at least about 90 degrees relative to an occlusal plane definedby a plane of contact between the patient's upper and lower teeth. 116.An oral device as in claim 112 wherein the soft palate landing surfacecomprises a wall extending superiorly from a posterior edge of thetongue constraint.
 117. An oral device as in claim 84 wherein theposterior opening lies in a first plane which is disposed at an angle ofat least about 45 degrees relative to an occlusal plane defined by aplane of contact between the patient's upper and lower teeth.
 118. Anoral device as in claim 117 wherein the first plane is about 45-180degrees relative to the occlusal plane.
 119. An oral device as in claim84 wherein the posterior opening is bounded on an inferior side by thetongue constraint and on a superior side by the patient's hard or softpalate.
 120. An oral device as in claim 84 wherein the soft palate hasan upper portion with an upper end joined to the hard palate and a lowerportion with a lower end which is unattached, and wherein the posterioropening is configured to apply negative pressure to the upper portionwhen the airway is open.
 121. A system for monitoring airway patencycomprising: an oral device positionable in a patient's oral cavity andadapted to maintain a continuous vacuum flow path from the patient'slips to the patient's soft palate and substantially seal the patient'sairway from the vacuum flow path; a vacuum source coupled to the oraldevice in fluid communication with the vacuum flow path; and a sensorcoupled to the oral device for detecting at least one condition withinthe oral cavity.
 122. A system as in claim 121 further comprising arecording device coupled to the sensor and adapted to record datareceived from the sensor over a time period.
 123. A system as in claim121 further comprising a controller coupled to the sensor and the vacuumsource for controlling the vacuum source in response to signalsgenerated by the sensor.
 124. A system as in claim 123 wherein thesensor comprises a pressure sensor and the controller is adapted toautomatically regulate the vacuum source so as to maintain asubstantially constant negative pressure in the oral cavity.
 125. Asystem as in claim 122 wherein the recording device comprises a memorydevice.
 126. A system as in claim 125 further comprising a computer incommunication with the memory device.
 127. A system as in claim 126further comprising a display adapted to display information from thememory device to the user.
 128. A system as in claim 126 furthercomprising a user input device adapted to transmit information from theuser to the computer.
 129. A system as in claim 121 wherein the sensoris attached to the oral device so as to be positionable in the oralcavity.
 130. A system as in claim 121 further comprising a tube attachedto the oral device and having a port located in the oral cavity when theoral device is positioned therein, the sensor being in communicationwith the tube outside the oral cavity.
 131. A system as in claim 121wherein the sensor comprises a pressure sensor adapted to detectpressure in the patient's oral cavity.
 132. A system as in claim 121wherein the sensor comprises an oximetry sensor adapted to detect oxygenlevels in the oral cavity or in the patient's tissue.
 133. A system asin claim 121 wherein the sensor comprises an impedance sensor adapted todetect contact between the oral device and tissues in the oral cavity.134. A system as in claim 121 wherein the sensor comprises anaccelerometer adapted to detect the orientation of the patient's head.135. A system as in claim 121 wherein the sensor comprises apiezoelectric sensor for detecting a sound selected from breathing,snoring, teeth grinding, or heartbeat.
 136. A system as in claim 121wherein the sensor comprises a temperature sensor.
 137. A system as inclaim 136 wherein the temperature sensor is adapted to detect thetemperature of air in or adjacent to the nasal airway.
 138. A system asin claim 121 further comprising a transmission device for electronicallytransmitting information from the recording device to an externaldevice.
 139. A system as in claim 138 wherein the transmission device isselected from a modem, a docking station, a cable connector, and awireless transmitter.
 140. A system as in claim 121 wherein the oraldevice is adapted to maintain the soft palate in sealing engagement withthe tongue such that the airway is substantially fluidly isolated fromthe vacuum flow path.
 141. A system as in claim 121 wherein the sensoris adapted to monitor whether the airway is substantially fluidlyisolated from the vacuum flow path.
 142. A system as in claim 141wherein the sensor is a pressure sensor for monitoring pressure in theoral cavity.
 143. A system as in claim 141 wherein the sensor is a flowsensor for monitoring flow rate through the vacuum flow path.
 144. Asystem as in claim 121 further comprising an alarm adapted to provide avisual or audible signal in response to data received from the sensor.145. A system as in claim 121 further comprising a liquid collector incommunication with the vacuum source for collecting liquid aspiratedfrom the oral cavity.
 146. A system as in claim 145 wherein the vacuumsource is adapted to automatically maintain substantially constantnegative pressure in the oral cavity when liquid is being aspirated.147. A system as in claim 122 wherein the time period is selectable bythe user to be any of a plurality of times periods.
 148. A system as inclaim 121 further comprising at least a second sensor for monitoring asecond condition in the oral cavity.